New common unarchive code.

3 files changed, 363 insertions, 470 deletions

diff --git a/libbb/Makefile.in b/libbb/Makefile.in
index e7ca9aa55..449d23c68 100644
--- a/libbb/Makefile.in
+++ b/libbb/Makefile.in
@@ -28,20 +28,22 @@ LIBBB_SRC:= \
         copy_file_chunk.c dump.c libc5.c device_open.c error_msg.c \
         error_msg_and_die.c fgets_str.c find_mount_point.c find_pid_by_name.c \
         find_root_device.c full_read.c full_write.c get_console.c \
-        get_last_path_component.c get_line_from_file.c gz_open.c human_readable.c \
-        isdirectory.c kernel_version.c loop.c mode_string.c module_syscalls.c mtab.c \
-        mtab_file.c my_getgrnam.c my_getgrgid.c my_getpwnam.c my_getpwnamegid.c \
-        my_getpwuid.c parse_mode.c parse_number.c perror_msg.c perror_msg_and_die.c \
-        print_file.c process_escape_sequence.c read_package_field.c recursive_action.c \
-        safe_read.c safe_strncpy.c syscalls.c syslog_msg_with_name.c time_string.c \
-        trim.c unzip.c uncompress.c vdprintf.c verror_msg.c vperror_msg.c wfopen.c \
-        xgetcwd.c xreadlink.c xregcomp.c interface.c remove_file.c last_char_is.c \
-        copyfd.c vherror_msg.c herror_msg.c herror_msg_and_die.c xgethostbyname.c \
-        dirname.c make_directory.c create_icmp_socket.c u_signal_names.c arith.c \
-        simplify_path.c inet_common.c inode_hash.c obscure.c pwd2spwd.c xfuncs.c \
-        correct_password.c change_identity.c setup_environment.c run_shell.c \
-        pw_encrypt.c restricted_shell.c xgethostbyname2.c create_icmp6_socket.c \
-       xconnect.c bb_asprintf.c
+        get_last_path_component.c get_line_from_file.c  \
+        human_readable.c isdirectory.c kernel_version.c loop.c \
+        mode_string.c module_syscalls.c mtab.c mtab_file.c my_getgrnam.c \
+        my_getgrgid.c my_getpwnam.c my_getpwnamegid.c my_getpwuid.c \
+        parse_mode.c parse_number.c perror_msg.c perror_msg_and_die.c \
+        print_file.c process_escape_sequence.c read_package_field.c \
+        recursive_action.c safe_read.c safe_strncpy.c syscalls.c \
+        syslog_msg_with_name.c time_string.c trim.c unzip.c uncompress.c \
+        vdprintf.c verror_msg.c vperror_msg.c wfopen.c xgetcwd.c xreadlink.c \
+        xregcomp.c interface.c remove_file.c last_char_is.c copyfd.c \
+        vherror_msg.c herror_msg.c herror_msg_and_die.c xgethostbyname.c \
+        dirname.c make_directory.c create_icmp_socket.c u_signal_names.c \
+        arith.c simplify_path.c inet_common.c inode_hash.c obscure.c \
+        pwd2spwd.c xfuncs.c correct_password.c change_identity.c \
+        setup_environment.c run_shell.c pw_encrypt.c restricted_shell.c \
+        xgethostbyname2.c create_icmp6_socket.c xconnect.c bb_asprintf.c
 
 LIBBB_OBJS=$(patsubst %.c,$(LIBBB_DIR)%.o, $(LIBBB_SRC))
 
diff --git a/libbb/unzip.c b/libbb/unzip.c
index d84067068..20bf88f55 100644
--- a/libbb/unzip.c
+++ b/libbb/unzip.c
@@ -65,114 +65,126 @@ static char *license_msg[] = {
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
 #include "config.h"
-#include "libbb.h"
+#include "busybox.h"
+#include "unarchive.h"
 
-#ifdef CONFIG_FEATURE_UNCOMPRESS
-int uncompress(FILE * in, FILE * out);
-#endif
-
-static FILE *in_file, *out_file;
+typedef struct huft_s {
+        unsigned char e;        /* number of extra bits or operation */
+        unsigned char b;        /* number of bits in this code or subcode */
+        union {
+                unsigned short n;       /* literal, length base, or distance base */
+                struct huft_s *t;       /* pointer to next level of table */
+        } v;
+} huft_t;
 
-/* these are freed by gz_close */
-static unsigned char *window;
-static unsigned long *crc_table;
+static int gunzip_src_fd;
+static int gunzip_dst_fd;
+unsigned int gunzip_bytes_out;  /* number of output bytes */
+static unsigned int gunzip_outbuf_count;        /* bytes in output buffer */
 
-static unsigned long crc;       /* shift register contents */
+/* This is used to sanify any unused bits from the bitbuffer 
+ * so they arent skipped when reading trailers (trailing headers) */
+unsigned char gunzip_in_buffer_count;
+unsigned char *gunzip_in_buffer;
 
-/* Return codes from gzip */
-#define ERROR 1
+/* gunzip_window size--must be a power of two, and
+ *  at least 32K for zip's deflate method */
+static const int gunzip_wsize = 0x8000;
 
-/*
- * window size--must be a power of two, and
- *  at least 32K for zip's deflate method
- */
-#define WSIZE 0x8000
+static unsigned char *gunzip_window;
+static unsigned int *gunzip_crc_table;
+unsigned int gunzip_crc;
 
 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
 #define BMAX 16 /* maximum bit length of any code (16 for explode) */
 #define N_MAX 288       /* maximum number of codes in any set */
 
-static long bytes_out;  /* number of output bytes */
-static unsigned long outcnt;    /* bytes in output buffer */
-
-static unsigned hufts;  /* track memory usage */
-static unsigned long bb;        /* bit buffer */
-static unsigned bk;             /* bits in bit buffer */
-
-typedef struct huft_s {
-        unsigned char e;        /* number of extra bits or operation */
-        unsigned char b;        /* number of bits in this code or subcode */
-        union {
-                unsigned short n;       /* literal, length base, or distance base */
-                struct huft_s *t;       /* pointer to next level of table */
-        } v;
-} huft_t;
+static unsigned int gunzip_hufts;       /* track memory usage */
+static unsigned int gunzip_bb;  /* bit buffer */
+static unsigned char gunzip_bk; /* bits in bit buffer */
 
 static const unsigned short mask_bits[] = {
-        0x0000,
-        0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+        0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
         0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
 };
 
-/* static int error_number = 0; */
-/* ========================================================================
- * Signal and error handler.
- */
+/* Copy lengths for literal codes 257..285 */
+static const unsigned short cplens[] = {
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+                67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
+};
+
+/* note: see note #13 above about the 258 in this list. */
+/* Extra bits for literal codes 257..285 */
+static const unsigned char cplext[] = {
+        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5,
+                5, 5, 5, 0, 99, 99
+};                                              /* 99==invalid */
+
+/* Copy offsets for distance codes 0..29 */
+static const unsigned short cpdist[] = {
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
+                769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
+};
+
+/* Extra bits for distance codes */
+static const unsigned char cpdext[] = {
+        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
+                11, 11, 12, 12, 13, 13
+};
+
+/* Tables for deflate from PKZIP's appnote.txt. */
+/* Order of the bit length code lengths */
+static const unsigned char border[] = {
+        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
+};
+
+static unsigned int fill_bitbuffer(unsigned int bitbuffer, unsigned int *current, const unsigned int required)
+{
+        while (*current < required) {
+                bitbuffer |= ((unsigned int) xread_char(gunzip_src_fd)) << *current;
+                *current += 8;
+        }
+
+        return(bitbuffer);
+}
 
 static void abort_gzip(void)
 {
         error_msg("gzip aborted\n");
-        exit(ERROR);
+        exit(-1);
 }
 
-static void make_crc_table(void)
+static void make_gunzip_crc_table(void)
 {
-        const unsigned long poly = 0xedb88320;  /* polynomial exclusive-or pattern */
+        const unsigned int poly = 0xedb88320;   /* polynomial exclusive-or pattern */
         unsigned short i;       /* counter for all possible eight bit values */
 
         /* initial shift register value */
-        crc = 0xffffffffL;
-        crc_table = (unsigned long *) malloc(256 * sizeof(unsigned long));
+        gunzip_crc = 0xffffffffL;
+        gunzip_crc_table = (unsigned int *) malloc(256 * sizeof(unsigned int));
 
         /* Compute and print table of CRC's, five per line */
         for (i = 0; i < 256; i++) {
-                unsigned long table_entry;      /* crc shift register */
-                char k;                 /* byte being shifted into crc apparatus */
+                unsigned int table_entry;       /* crc shift register */
+                unsigned char k;        /* byte being shifted into crc apparatus */
 
                 table_entry = i;
                 /* The idea to initialize the register with the byte instead of
                    * zero was stolen from Haruhiko Okumura's ar002
                  */
                 for (k = 8; k; k--) {
-                        table_entry =
-                                table_entry & 1 ? (table_entry >> 1) ^ poly : table_entry >>
-                                1;
-                }
-                crc_table[i] = table_entry;
+                        if (table_entry & 1) {
+                                table_entry = (table_entry >> 1) ^ poly;
+                        } else {
+                                table_entry >>= 1;
         }
-}
-
-/* ===========================================================================
- * Write the output window window[0..outcnt-1] and update crc and bytes_out.
- * (Used for the decompressed data only.)
- */
-static void flush_window(void)
-{
-        int n;
-
-        if (outcnt == 0)
-                return;
-
-        for (n = 0; n < outcnt; n++) {
-                crc = crc_table[((int) crc ^ (window[n])) & 0xff] ^ (crc >> 8);
         }
-
-        if (fwrite(window, 1, outcnt, out_file) != outcnt) {
-                error_msg_and_die("Couldnt write");
+                gunzip_crc_table[i] = table_entry;
         }
-        bytes_out += (unsigned long) outcnt;
-        outcnt = 0;
 }
 
 /*
@@ -183,7 +195,8 @@ static void flush_window(void)
  */
 static int huft_free(huft_t * t)
 {
-        huft_t *p, *q;
+        huft_t *p;
+        huft_t *q;
 
         /* Go through linked list, freeing from the malloced (t[-1]) address. */
         p = t;
@@ -195,8 +208,6 @@ static int huft_free(huft_t * t)
         return 0;
 }
 
-typedef unsigned char extra_bits_t;
-
 /* Given a list of code lengths and a maximum table size, make a set of
  * tables to decode that set of codes.  Return zero on success, one if
  * the given code set is incomplete (the tables are still built in this
@@ -213,7 +224,7 @@ typedef unsigned char extra_bits_t;
  */
 static int huft_build(unsigned int *b, const unsigned int n,
                                           const unsigned int s, const unsigned short *d,
-                                          const extra_bits_t * e, huft_t ** t, int *m)
+                                          const unsigned char *e, huft_t ** t, int *m)
 {
         unsigned a;                     /* counter for codes of length k */
         unsigned c[BMAX + 1];   /* bit length count table */
@@ -251,26 +262,35 @@ static int huft_build(unsigned int *b, const unsigned int n,
 
         /* Find minimum and maximum length, bound *m by those */
         l = *m;
-        for (j = 1; j <= BMAX; j++)
-                if (c[j])
+        for (j = 1; j <= BMAX; j++) {
+                if (c[j]) {
                         break;
+                }
+        }
         k = j;                          /* minimum code length */
-        if ((unsigned) l < j)
+        if ((unsigned) l < j) {
                 l = j;
-        for (i = BMAX; i; i--)
-                if (c[i])
+        }
+        for (i = BMAX; i; i--) {
+                if (c[i]) {
                         break;
+                }
+        }
         g = i;                          /* maximum code length */
-        if ((unsigned) l > i)
+        if ((unsigned) l > i) {
                 l = i;
+        }
         *m = l;
 
         /* Adjust last length count to fill out codes, if needed */
-        for (y = 1 << j; j < i; j++, y <<= 1)
-                if ((y -= c[j]) < 0)
+        for (y = 1 << j; j < i; j++, y <<= 1) {
+                if ((y -= c[j]) < 0) {
                         return 2;       /* bad input: more codes than bits */
-        if ((y -= c[i]) < 0)
+                }
+        }
+        if ((y -= c[i]) < 0) {
                 return 2;
+        }
         c[i] += y;
 
         /* Generate starting offsets into the value table for each length */
@@ -285,8 +305,9 @@ static int huft_build(unsigned int *b, const unsigned int n,
         p = b;
         i = 0;
         do {
-                if ((j = *p++) != 0)
+                if ((j = *p++) != 0) {
                         v[x[j]++] = i;
+                }
         } while (++i < n);
 
         /* Generate the Huffman codes and for each, make the table entries */
@@ -314,8 +335,9 @@ static int huft_build(unsigned int *b, const unsigned int n,
                                         f -= a + 1;     /* deduct codes from patterns left */
                                         xp = c + k;
                                         while (++j < z) {       /* try smaller tables up to z bits */
-                                                if ((f <<= 1) <= *++xp)
+                                                if ((f <<= 1) <= *++xp) {
                                                         break;  /* enough codes to use up j bits */
+                                                }
                                                 f -= *xp;       /* else deduct codes from patterns */
                                         }
                                 }
@@ -324,7 +346,7 @@ static int huft_build(unsigned int *b, const unsigned int n,
                                 /* allocate and link in new table */
                                 q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
 
-                                hufts += z + 1; /* track memory usage */
+                                gunzip_hufts += z + 1;  /* track memory usage */
                                 *t = q + 1;     /* link to list for huft_free() */
                                 *(t = &(q->v.t)) = NULL;
                                 u[h] = ++q;     /* table starts after link */
@@ -342,9 +364,9 @@ static int huft_build(unsigned int *b, const unsigned int n,
 
                         /* set up table entry in r */
                         r.b = (unsigned char) (k - w);
-                        if (p >= v + n)
+                        if (p >= v + n) {
                                 r.e = 99;       /* out of values--invalid code */
-                        else if (*p < s) {
+                        } else if (*p < s) {
                                 r.e = (unsigned char) (*p < 256 ? 16 : 15);     /* 256 is end-of-block code */
                                 r.v.n = (unsigned short) (*p);  /* simple code is just the value */
                                 p++;    /* one compiler does not like *p++ */
@@ -355,12 +377,14 @@ static int huft_build(unsigned int *b, const unsigned int n,
 
                         /* fill code-like entries with r */
                         f = 1 << (k - w);
-                        for (j = i >> w; j < z; j += f)
+                        for (j = i >> w; j < z; j += f) {
                                 q[j] = r;
+                        }
 
                         /* backwards increment the k-bit code i */
-                        for (j = 1 << (k - 1); i & j; j >>= 1)
+                        for (j = 1 << (k - 1); i & j; j >>= 1) {
                                 i ^= j;
+                        }
                         i ^= j;
 
                         /* backup over finished tables */
@@ -374,6 +398,25 @@ static int huft_build(unsigned int *b, const unsigned int n,
         return y != 0 && g != 1;
 }
 
+/* ===========================================================================
+ * Write the output gunzip_window gunzip_window[0..gunzip_outbuf_count-1] and update crc and gunzip_bytes_out.
+ * (Used for the decompressed data only.)
+ */
+static void flush_gunzip_window(void)
+{
+        int n;
+
+        for (n = 0; n < gunzip_outbuf_count; n++) {
+                gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8);
+        }
+
+        if (write(gunzip_dst_fd, gunzip_window, gunzip_outbuf_count) != gunzip_outbuf_count) {
+                error_msg_and_die("Couldnt write");
+        }
+        gunzip_bytes_out += gunzip_outbuf_count;
+        gunzip_outbuf_count = 0;
+}
+
 /*
  * inflate (decompress) the codes in a deflated (compressed) block.
  * Return an error code or zero if it all goes ok.
@@ -381,32 +424,26 @@ static int huft_build(unsigned int *b, const unsigned int n,
  * tl, td: literal/length and distance decoder tables
  * bl, bd: number of bits decoded by tl[] and td[]
  */
-static int inflate_codes(huft_t * tl, huft_t * td, int bl, int bd)
+static int inflate_codes(huft_t * tl, huft_t * td, const unsigned int bl, const unsigned int bd)
 {
-        register unsigned long e;       /* table entry flag/number of extra bits */
-        unsigned long n, d;     /* length and index for copy */
-        unsigned long w;        /* current window position */
+        unsigned int e; /* table entry flag/number of extra bits */
+        unsigned int n, d;      /* length and index for copy */
+        unsigned int w; /* current gunzip_window position */
         huft_t *t;                      /* pointer to table entry */
-        unsigned ml, md;        /* masks for bl and bd bits */
-        register unsigned long b;       /* bit buffer */
-        register unsigned k;    /* number of bits in bit buffer */
-        register int input_char;
+        unsigned int ml, md;    /* masks for bl and bd bits */
+        unsigned int b; /* bit buffer */
+        unsigned int k;                 /* number of bits in bit buffer */
 
         /* make local copies of globals */
-        b = bb;                         /* initialize bit buffer */
-        k = bk;
-        w = outcnt;                     /* initialize window position */
+        b = gunzip_bb;                          /* initialize bit buffer */
+        k = gunzip_bk;
+        w = gunzip_outbuf_count;                        /* initialize gunzip_window position */
 
         /* inflate the coded data */
         ml = mask_bits[bl];     /* precompute masks for speed */
         md = mask_bits[bd];
-        for (;;) {                      /* do until end of block */
-                while (k < (unsigned) bl) {
-                        input_char = fgetc(in_file);
-                        if (input_char == EOF) return 1;
-                        b |= ((unsigned long)input_char) << k;
-                        k += 8;
-                }
+        while (1) {                     /* do until end of block */
+                b = fill_bitbuffer(b, &k, bl);
                 if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
                         do {
                                 if (e == 99) {
@@ -415,20 +452,16 @@ static int inflate_codes(huft_t * tl, huft_t * td, int bl, int bd)
                                 b >>= t->b;
                                 k -= t->b;
                                 e -= 16;
-                                while (k < e) {
-                                        input_char = fgetc(in_file);
-                                        if (input_char == EOF) return 1;
-                                        b |= ((unsigned long)input_char) << k;
-                                        k += 8;
-                                }
+                                b = fill_bitbuffer(b, &k, e);
                         } while ((e =
                                           (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
                 b >>= t->b;
                 k -= t->b;
                 if (e == 16) {  /* then it's a literal */
-                        window[w++] = (unsigned char) t->v.n;
-                        if (w == WSIZE) {
-                                outcnt = (w), flush_window();
+                        gunzip_window[w++] = (unsigned char) t->v.n;
+                        if (w == gunzip_wsize) {
+                                gunzip_outbuf_count = (w);
+                                flush_gunzip_window();
                                 w = 0;
                         }
                 } else {                /* it's an EOB or a length */
@@ -439,24 +472,13 @@ static int inflate_codes(huft_t * tl, huft_t * td, int bl, int bd)
                         }
 
                         /* get length of block to copy */
-                        while (k < e) {
-                                input_char = fgetc(in_file);
-                                if (input_char == EOF) return 1;
-                                b |= ((unsigned long)input_char) << k;
-                                k += 8;
-                        }
+                        b = fill_bitbuffer(b, &k, e);
                         n = t->v.n + ((unsigned) b & mask_bits[e]);
                         b >>= e;
                         k -= e;
 
                         /* decode distance of block to copy */
-                        while (k < (unsigned) bd) {
-                                input_char = fgetc(in_file);
-                                if (input_char == EOF) return 1;
-                                b |= ((unsigned long)input_char) << k;
-                                k += 8;
-                        }
-
+                        b = fill_bitbuffer(b, &k, bd);
                         if ((e = (t = td + ((unsigned) b & md))->e) > 16)
                                 do {
                                         if (e == 99)
@@ -464,23 +486,13 @@ static int inflate_codes(huft_t * tl, huft_t * td, int bl, int bd)
                                         b >>= t->b;
                                         k -= t->b;
                                         e -= 16;
-                                        while (k < e) {
-                                                input_char = fgetc(in_file);
-                                                if (input_char == EOF) return 1;
-                                                b |= ((unsigned long)input_char) << k;
-                                                k += 8;
-                                        }
+                                        b = fill_bitbuffer(b, &k, e);
                                 } while ((e =
                                                   (t =
                                                    t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
                         b >>= t->b;
                         k -= t->b;
-                        while (k < e) {
-                                input_char = fgetc(in_file);
-                                if (input_char == EOF) return 1;
-                                b |= ((unsigned long)input_char) << k;
-                                k += 8;
-                        }
+                        b = fill_bitbuffer(b, &k, e);
                         d = w - t->v.n - ((unsigned) b & mask_bits[e]);
                         b >>= e;
                         k -= e;
@@ -489,60 +501,38 @@ static int inflate_codes(huft_t * tl, huft_t * td, int bl, int bd)
                         do {
                                 n -= (e =
                                           (e =
-                                           WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n : e);
-#if !defined(NOMEMCPY) && !defined(DEBUG)
+                                           gunzip_wsize - ((d &= gunzip_wsize - 1) > w ? d : w)) > n ? n : e);
+                           /* copy to new buffer to prevent possible overwrite */
                                 if (w - d >= e) {       /* (this test assumes unsigned comparison) */
-                                        memcpy(window + w, window + d, e);
+                                        memcpy(gunzip_window + w, gunzip_window + d, e);
                                         w += e;
                                         d += e;
-                                } else  /* do it slow to avoid memcpy() overlap */
-#endif                                                  /* !NOMEMCPY */
+                                } else {
+                                   /* do it slow to avoid memcpy() overlap */
+                                   /* !NOMEMCPY */
                                         do {
-                                                window[w++] = window[d++];
+                                                gunzip_window[w++] = gunzip_window[d++];
                                         } while (--e);
-                                if (w == WSIZE) {
-                                        outcnt = (w), flush_window();
+                                }
+                                if (w == gunzip_wsize) {
+                                        gunzip_outbuf_count = (w);
+                                        flush_gunzip_window();
                                         w = 0;
                                 }
+
                         } while (n);
                 }
         }
 
         /* restore the globals from the locals */
-        outcnt = w;                     /* restore global window pointer */
-        bb = b;                         /* restore global bit buffer */
-        bk = k;
+        gunzip_outbuf_count = w;                        /* restore global gunzip_window pointer */
+        gunzip_bb = b;                          /* restore global bit buffer */
+        gunzip_bk = k;
 
         /* done */
         return 0;
 }
 
-static const unsigned short cplens[] = {        /* Copy lengths for literal codes 257..285 */
-        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
-        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
-};
-
-/* note: see note #13 above about the 258 in this list. */
-static const extra_bits_t cplext[] = {  /* Extra bits for literal codes 257..285 */
-        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
-        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
-};                                              /* 99==invalid */
-static const unsigned short cpdist[] = {        /* Copy offsets for distance codes 0..29 */
-        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
-        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
-        8193, 12289, 16385, 24577
-};
-static const extra_bits_t cpdext[] = {  /* Extra bits for distance codes */
-        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
-        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
-        12, 12, 13, 13
-};
-
-/* Tables for deflate from PKZIP's appnote.txt. */
-static const extra_bits_t border[] = {  /* Order of the bit length code lengths */
-        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
-};
-
 /*
  * decompress an inflated block
  * e: last block flag
@@ -552,53 +542,43 @@ static const extra_bits_t border[] = {	/* Order of the bit length code lengths *
 static int inflate_block(int *e)
 {
         unsigned t;                     /* block type */
-        register unsigned long b;       /* bit buffer */
-        register unsigned k;    /* number of bits in bit buffer */
-        int input_char;
+        register unsigned int b;        /* bit buffer */
+        unsigned int k; /* number of bits in bit buffer */
 
         /* make local bit buffer */
-        b = bb;
-        k = bk;
+
+        b = gunzip_bb;
+        k = gunzip_bk;
 
         /* read in last block bit */
-        while (k < 1) {
-                input_char = fgetc(in_file);
-                if (input_char == EOF) return 1;
-                b |= ((unsigned long)input_char) << k;
-                k += 8;
-        }
+        b = fill_bitbuffer(b, &k, 1);
         *e = (int) b & 1;
         b >>= 1;
         k -= 1;
 
         /* read in block type */
-        while (k < 2) {
-                input_char = fgetc(in_file);
-                if (input_char == EOF) return 1;
-                b |= ((unsigned long)input_char) << k;
-                k += 8;
-        }
+        b = fill_bitbuffer(b, &k, 2);
         t = (unsigned) b & 3;
         b >>= 2;
         k -= 2;
 
         /* restore the global bit buffer */
-        bb = b;
-        bk = k;
+        gunzip_bb = b;
+        gunzip_bk = k;
 
         /* inflate that block type */
         switch (t) {
         case 0:                 /* Inflate stored */
         {
-                unsigned long n;        /* number of bytes in block */
-                unsigned long w;        /* current window position */
-                register unsigned long b_stored;        /* bit buffer */
-                register unsigned long k_stored;        /* number of bits in bit buffer */
+                unsigned int n; /* number of bytes in block */
+                unsigned int w; /* current gunzip_window position */
+                unsigned int b_stored;  /* bit buffer */
+                unsigned int k_stored;  /* number of bits in bit buffer */
 
                 /* make local copies of globals */
-                b_stored = bb;  /* initialize bit buffer */
-                k_stored = bk;
-                w = outcnt;             /* initialize window position */
+                b_stored = gunzip_bb;   /* initialize bit buffer */
+                k_stored = gunzip_bk;
+                w = gunzip_outbuf_count;                /* initialize gunzip_window position */
 
                 /* go to byte boundary */
                 n = k_stored & 7;
@@ -606,21 +586,12 @@ static int inflate_block(int *e)
                 k_stored -= n;
 
                 /* get the length and its complement */
-                while (k_stored < 16) {
-                        input_char = fgetc(in_file);
-                        if (input_char == EOF) return 1;
-                        b_stored |= ((unsigned long)input_char) << k_stored;
-                        k_stored += 8;
-                }
+                b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
                 n = ((unsigned) b_stored & 0xffff);
                 b_stored >>= 16;
                 k_stored -= 16;
-                while (k_stored < 16) {
-                        input_char = fgetc(in_file);
-                        if (input_char == EOF) return 1;
-                        b_stored |= ((unsigned long)input_char) << k_stored;
-                        k_stored += 8;
-                }
+
+                b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
                 if (n != (unsigned) ((~b_stored) & 0xffff)) {
                         return 1;       /* error in compressed data */
                 }
@@ -629,15 +600,11 @@ static int inflate_block(int *e)
 
                 /* read and output the compressed data */
                 while (n--) {
-                        while (k_stored < 8) {
-                                input_char = fgetc(in_file);
-                                if (input_char == EOF) return 1;
-                                b_stored |= ((unsigned long)input_char) << k_stored;
-                                k_stored += 8;
-                        }
-                        window[w++] = (unsigned char) b_stored;
-                        if (w == (unsigned long) WSIZE) {
-                                outcnt = (w), flush_window();
+                        b_stored = fill_bitbuffer(b_stored, &k_stored, 8);
+                        gunzip_window[w++] = (unsigned char) b_stored;
+                        if (w == (unsigned int) gunzip_wsize) {
+                                gunzip_outbuf_count = (w);
+                                flush_gunzip_window();
                                 w = 0;
                         }
                         b_stored >>= 8;
@@ -645,9 +612,9 @@ static int inflate_block(int *e)
                 }
 
                 /* restore the globals from the locals */
-                outcnt = w;             /* restore global window pointer */
-                bb = b_stored;  /* restore global bit buffer */
-                bk = k_stored;
+                gunzip_outbuf_count = w;                /* restore global gunzip_window pointer */
+                gunzip_bb = b_stored;   /* restore global bit buffer */
+                gunzip_bk = k_stored;
                 return 0;
         }
         case 1:                 /* Inflate fixed 
@@ -659,8 +626,8 @@ static int inflate_block(int *e)
                 int i;                  /* temporary variable */
                 huft_t *tl;             /* literal/length code table */
                 huft_t *td;             /* distance code table */
-                int bl;                 /* lookup bits for tl */
-                int bd;                 /* lookup bits for td */
+                unsigned int bl;                        /* lookup bits for tl */
+                unsigned int bd;                        /* lookup bits for td */
                 unsigned int l[288];    /* length list for huft_build */
 
                 /* set up literal table */
@@ -692,8 +659,9 @@ static int inflate_block(int *e)
                 }
 
                 /* decompress until an end-of-block code */
-                if (inflate_codes(tl, td, bl, bd))
+                if (inflate_codes(tl, td, bl, bd)) {
                         return 1;
+                }
 
                 /* free the decoding tables, return */
                 huft_free(tl);
@@ -705,53 +673,41 @@ static int inflate_block(int *e)
                 const int dbits = 6;    /* bits in base distance lookup table */
                 const int lbits = 9;    /* bits in base literal/length lookup table */
 
-                int i;                  /* temporary variables */
-                unsigned j;
-                unsigned l;             /* last length */
-                unsigned m;             /* mask for bit lengths table */
-                unsigned n;             /* number of lengths to get */
                 huft_t *tl;             /* literal/length code table */
                 huft_t *td;             /* distance code table */
-                int bl;                 /* lookup bits for tl */
-                int bd;                 /* lookup bits for td */
-                unsigned nb;    /* number of bit length codes */
-                unsigned nl;    /* number of literal/length codes */
-                unsigned nd;    /* number of distance codes */
-
-                unsigned ll[286 + 30];  /* literal/length and distance code lengths */
-                register unsigned long b_dynamic;       /* bit buffer */
-                register unsigned k_dynamic;    /* number of bits in bit buffer */
+                unsigned int i;                 /* temporary variables */
+                unsigned int j;
+                unsigned int l;         /* last length */
+                unsigned int m;         /* mask for bit lengths table */
+                unsigned int n;         /* number of lengths to get */
+                unsigned int bl;                        /* lookup bits for tl */
+                unsigned int bd;                        /* lookup bits for td */
+                unsigned int nb;        /* number of bit length codes */
+                unsigned int nl;        /* number of literal/length codes */
+                unsigned int nd;        /* number of distance codes */
+
+                unsigned int ll[286 + 30];      /* literal/length and distance code lengths */
+                unsigned int b_dynamic; /* bit buffer */
+                unsigned int k_dynamic; /* number of bits in bit buffer */
 
                 /* make local bit buffer */
-                b_dynamic = bb;
-                k_dynamic = bk;
+                b_dynamic = gunzip_bb;
+                k_dynamic = gunzip_bk;
 
                 /* read in table lengths */
-                while (k_dynamic < 5) {
-                        input_char = fgetc(in_file);
-                        if (input_char == EOF) return 1;
-                        b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                        k_dynamic += 8;
-                }
-                nl = 257 + ((unsigned) b_dynamic & 0x1f);       /* number of literal/length codes */
+                b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
+                nl = 257 + ((unsigned int) b_dynamic & 0x1f);   /* number of literal/length codes */
+
                 b_dynamic >>= 5;
                 k_dynamic -= 5;
-                while (k_dynamic < 5) {
-                        input_char = fgetc(in_file);
-                        if (input_char == EOF) return 1;
-                        b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                        k_dynamic += 8;
-                }
-                nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
+                b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
+                nd = 1 + ((unsigned int) b_dynamic & 0x1f);     /* number of distance codes */
+
                 b_dynamic >>= 5;
                 k_dynamic -= 5;
-                while (k_dynamic < 4) {
-                        input_char = fgetc(in_file);
-                        if (input_char == EOF) return 1;
-                        b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                        k_dynamic += 8;
-                }
-                nb = 4 + ((unsigned) b_dynamic & 0xf);  /* number of bit length codes */
+                b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 4);
+                nb = 4 + ((unsigned int) b_dynamic & 0xf);      /* number of bit length codes */
+
                 b_dynamic >>= 4;
                 k_dynamic -= 4;
                 if (nl > 286 || nd > 30) {
@@ -760,13 +716,8 @@ static int inflate_block(int *e)
 
                 /* read in bit-length-code lengths */
                 for (j = 0; j < nb; j++) {
-                        while (k_dynamic < 3) {
-                                input_char = fgetc(in_file);
-                                if (input_char == EOF) return 1;
-                                b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                                k_dynamic += 8;
-                        }
-                        ll[border[j]] = (unsigned) b_dynamic & 7;
+                        b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
+                        ll[border[j]] = (unsigned int) b_dynamic & 7;
                         b_dynamic >>= 3;
                         k_dynamic -= 3;
                 }
@@ -776,7 +727,8 @@ static int inflate_block(int *e)
 
                 /* build decoding table for trees--single level, 7 bit lookup */
                 bl = 7;
-                if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0) {
+                i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl);
+                if (i != 0) {
                         if (i == 1) {
                                 huft_free(tl);
                         }
@@ -787,46 +739,31 @@ static int inflate_block(int *e)
                 n = nl + nd;
                 m = mask_bits[bl];
                 i = l = 0;
-                while ((unsigned) i < n) {
-                        while (k_dynamic < (unsigned) bl) {
-                                input_char = fgetc(in_file);
-                                if (input_char == EOF) return 1;
-                                b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                                k_dynamic += 8;
-                        }
-                        j = (td = tl + ((unsigned) b_dynamic & m))->b;
+                while ((unsigned int) i < n) {
+                        b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, (unsigned int)bl);
+                        j = (td = tl + ((unsigned int) b_dynamic & m))->b;
                         b_dynamic >>= j;
                         k_dynamic -= j;
                         j = td->v.n;
                         if (j < 16) {   /* length of code in bits (0..15) */
                                 ll[i++] = l = j;        /* save last length in l */
                         } else if (j == 16) {   /* repeat last length 3 to 6 times */
-                                while (k_dynamic < 2) {
-                                        input_char = fgetc(in_file);
-                                        if (input_char == EOF) return 1;
-                                        b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                                        k_dynamic += 8;
-                                }
-                                j = 3 + ((unsigned) b_dynamic & 3);
+                                b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 2);
+                                j = 3 + ((unsigned int) b_dynamic & 3);
                                 b_dynamic >>= 2;
                                 k_dynamic -= 2;
-                                if ((unsigned) i + j > n) {
+                                if ((unsigned int) i + j > n) {
                                         return 1;
                                 }
                                 while (j--) {
                                         ll[i++] = l;
                                 }
                         } else if (j == 17) {   /* 3 to 10 zero length codes */
-                                while (k_dynamic < 3) {
-                                        input_char = fgetc(in_file);
-                                        if (input_char == EOF) return 1;
-                                        b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                                        k_dynamic += 8;
-                                }
-                                j = 3 + ((unsigned) b_dynamic & 7);
+                                b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
+                                j = 3 + ((unsigned int) b_dynamic & 7);
                                 b_dynamic >>= 3;
                                 k_dynamic -= 3;
-                                if ((unsigned) i + j > n) {
+                                if ((unsigned int) i + j > n) {
                                         return 1;
                                 }
                                 while (j--) {
@@ -834,16 +771,11 @@ static int inflate_block(int *e)
                                 }
                                 l = 0;
                         } else {        /* j == 18: 11 to 138 zero length codes */
-                                while (k_dynamic < 7) {
-                                        input_char = fgetc(in_file);
-                                        if (input_char == EOF) return 1;
-                                        b_dynamic |= ((unsigned long)input_char) << k_dynamic;
-                                        k_dynamic += 8;
-                                }
-                                j = 11 + ((unsigned) b_dynamic & 0x7f);
+                                b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 7);
+                                j = 11 + ((unsigned int) b_dynamic & 0x7f);
                                 b_dynamic >>= 7;
                                 k_dynamic -= 7;
-                                if ((unsigned) i + j > n) {
+                                if ((unsigned int) i + j > n) {
                                         return 1;
                                 }
                                 while (j--) {
@@ -857,22 +789,24 @@ static int inflate_block(int *e)
                 huft_free(tl);
 
                 /* restore the global bit buffer */
-                bb = b_dynamic;
-                bk = k_dynamic;
+                gunzip_bb = b_dynamic;
+                gunzip_bk = k_dynamic;
 
                 /* build the decoding tables for literal/length and distance codes */
                 bl = lbits;
+
                 if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
                         if (i == 1) {
-                                error_msg("Incomplete literal tree");
+                                error_msg_and_die("Incomplete literal tree");
                                 huft_free(tl);
                         }
                         return i;       /* incomplete code set */
                 }
+
                 bd = dbits;
                 if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
                         if (i == 1) {
-                                error_msg("incomplete distance tree");
+                                error_msg_and_die("incomplete distance tree");
                                 huft_free(td);
                         }
                         huft_free(tl);
@@ -880,8 +814,9 @@ static int inflate_block(int *e)
                 }
 
                 /* decompress until an end-of-block code */
-                if (inflate_codes(tl, td, bl, bd))
+                if (inflate_codes(tl, td, bl, bd)) {
                         return 1;
+                }
 
                 /* free the decoding tables, return */
                 huft_free(tl);
@@ -890,6 +825,7 @@ static int inflate_block(int *e)
         }
         default:
                 /* bad block type */
+                error_msg("bad block type %d\n", t);
                 return 2;
         }
 }
@@ -897,72 +833,24 @@ static int inflate_block(int *e)
 /*
  * decompress an inflated entry
  *
- * GLOBAL VARIABLES: outcnt, bk, bb, hufts, inptr
+ * GLOBAL VARIABLES: gunzip_outbuf_count, bk, gunzip_bb, hufts, inptr
  */
-extern int inflate(FILE * in, FILE * out)
+extern int inflate(int in, int out)
 {
+        typedef void (*sig_type) (int);
         int e;                          /* last block flag */
         int r;                          /* result code */
         unsigned h = 0;         /* maximum struct huft's malloc'ed */
 
-        /* initialize window, bit buffer */
-        outcnt = 0;
-        bk = 0;
-        bb = 0;
-
-        in_file = in;
-        out_file = out;
-
         /* Allocate all global buffers (for DYN_ALLOC option) */
-        window = xmalloc((size_t) (((2L * WSIZE) + 1L) * sizeof(unsigned char)));
-        bytes_out = 0L;
+        gunzip_window = xmalloc(0x8000);
+        gunzip_outbuf_count = 0;
+        gunzip_bytes_out = 0;
 
-        /* Create the crc table */
-        make_crc_table();
+        gunzip_src_fd = in;
+        gunzip_dst_fd = out;
 
-        /* decompress until the last block */
-        do {
-                hufts = 0;
-                if ((r = inflate_block(&e)) != 0) {
-                        return r;
-                }
-                if (hufts > h) {
-                        h = hufts;
-                }
-        } while (!e);
-
-        /* Undo too much lookahead. The next read will be byte aligned so we
-         * can discard unused bits in the last meaningful byte.
-         */
-        while (bk >= 8) {
-                bk -= 8;
-                ungetc((bb << bk), in_file);
-        }
-
-        /* flush out window */
-        flush_window();
-        free(window);
-        free(crc_table);
-
-        /* return success */
-        return 0;
-}
-
-/* ===========================================================================
- * Unzip in to out.  This routine works on gzip files only.
- *
- * IN assertions: the buffer inbuf contains already the beginning of
- *   the compressed data, from offsets inptr to insize-1 included.
- *   The magic header has already been checked. The output buffer is cleared.
- * in, out: input and output file descriptors
- */
-extern int unzip(FILE * l_in_file, FILE * l_out_file)
-{
-        unsigned char buf[8];   /* extended local header */
-        unsigned char flags;    /* compression flags */
-        typedef void (*sig_type) (int);
-        unsigned short i;
-        unsigned char magic[2];
+        gunzip_in_buffer = malloc(8);
 
         if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
                 (void) signal(SIGINT, (sig_type) abort_gzip);
@@ -973,97 +861,44 @@ extern int unzip(FILE * l_in_file, FILE * l_out_file)
         }
 #endif
 
-        magic[0] = fgetc(l_in_file);
-        magic[1] = fgetc(l_in_file);
-
-#ifdef CONFIG_FEATURE_UNCOMPRESS
-        /* Magic header for compress files, 1F 9d = \037\235 */
-        if ((magic[0] == 0x1F) && (magic[1] == 0x9d)) {
-                return uncompress(l_in_file, l_out_file);
-        }
-#endif
-
-        /* Magic header for gzip files, 1F 8B = \037\213 */
-        if ((magic[0] != 0x1F) || (magic[1] != 0x8b)) {
-                error_msg("Invalid gzip magic");
-                return EXIT_FAILURE;
-        }
-
-        /* Check the compression method */
-        if (fgetc(l_in_file) != 8) /* also catches EOF */ {
-                error_msg("Unknown compression method");
-                return (-1);
-        }
-
-        flags = (unsigned char) fgetc(l_in_file);
-
-        /* Ignore time stamp(4), extra flags(1), OS type(1) */
-        for (i = 0; i < 6; i++) {
-                fgetc(l_in_file);
-        }
+        /* initialize gunzip_window, bit buffer */
+        gunzip_bk = 0;
+        gunzip_bb = 0;
 
-        if (flags & 0x04) {
-                /* bit 2 set: extra field present */
-                const unsigned short extra =
-                        fgetc(l_in_file) + (fgetc(l_in_file) << 8);
-                if (feof(in_file)) return 1;
-                for (i = 0; i < extra; i++) {
-                        fgetc(l_in_file);
-                }
-        }
-
-        /* Discard original name if any */
-        if (flags & 0x08) {
-                /* bit 3 set: original file name present */
-                while (fgetc(l_in_file) != 0 && !feof(l_in_file));      /* null */
-        }
+        /* Create the crc table */
+        make_gunzip_crc_table();
 
-        /* Discard file comment if any */
-        if (flags & 0x10) {
-                /* bit 4 set: file comment present */
-                while (fgetc(l_in_file) != 0 && !feof(l_in_file));      /* null */
+        /* decompress until the last block */
+        do {
+                gunzip_hufts = 0;
+                r = inflate_block(&e);
+                if (r != 0) {
+                        error_msg_and_die("inflate error %d", r);
+                        return r;
         }
-
-        /* Decompress */
-        if (inflate(l_in_file, l_out_file) != 0) {
-                error_msg("invalid compressed data--format violated");
+                if (gunzip_hufts > h) {
+                        h = gunzip_hufts;
         }
+        } while (!e);
 
-        /* Get the crc and original length
-         * crc32  (see algorithm.doc)
-         * uncompressed input size modulo 2^32
-         */
-        fread(buf, 1, 8, l_in_file);
-
-        /* Validate decompression - crc */
-        if ((unsigned int) ((buf[0] | (buf[1] << 8)) |
-                                                ((buf[2] | (buf[3] << 8)) << 16)) !=
-                (crc ^ 0xffffffffL)) {
-                error_msg("invalid compressed data--crc error");
-        }
-        /* Validate decompression - size */
-        if (((buf[4] | (buf[5] << 8)) | ((buf[6] | (buf[7] << 8)) << 16)) !=
-                (unsigned long) bytes_out) {
-                error_msg("invalid compressed data--length error");
+        /* write any buffered uncompressed data */
+        flush_gunzip_window();
+        free(gunzip_window);
+
+        /* Cleanup */
+        free(gunzip_crc_table);
+
+        /* Store unused bytes in a global buffer so calling applets can access it */
+        gunzip_in_buffer_count = 0;
+        if (gunzip_bk >= 8) {
+                /* Undo too much lookahead. The next read will be byte aligned
+                 * so we can discard unused bits in the last meaningful byte. */
+                gunzip_in_buffer[gunzip_in_buffer_count] = gunzip_bb & 0xff;
+                gunzip_in_buffer_count++;
+                gunzip_bb >>= 8;
+                gunzip_bk -= 8;
         }
 
+        /* return success */
         return 0;
 }
-
-/*
- * This needs access to global variables window and crc_table, so its not in its own file.
- */
-extern void gz_close(int gunzip_pid)
-{
-        if (kill(gunzip_pid, SIGTERM) == -1) {
-                error_msg_and_die
-                        ("***  Couldnt kill old gunzip process *** aborting");
-        }
-
-        if (waitpid(gunzip_pid, NULL, 0) == -1) {
-                printf("Couldnt wait ?");
-        }
-
-        free(window);
-        free(crc_table);
-}
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 869c04a4c..2249e263a 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -19,10 +19,13 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
+#include <sys/types.h>
+#include <sys/stat.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include "libbb.h"
 
 
@@ -85,6 +88,59 @@ FILE *xfopen(const char *path, const char *mode)
         return fp;
 }
 
+extern int xopen(const char *pathname, int flags)
+{
+        int ret;
+        
+        ret = open(pathname, flags);
+        if (ret == -1) {
+                perror_msg_and_die("%s", pathname);
+        }
+        return ret;
+}
+
+extern ssize_t xread(int fd, void *buf, size_t count)
+{
+        ssize_t size;
+
+        size = read(fd, buf, count);
+        if (size == -1) {
+                perror_msg_and_die("Read error");
+        }
+        return(size);
+}
+
+extern void xread_all(int fd, void *buf, size_t count)
+{
+        ssize_t size;
+
+        size = xread(fd, buf, count);
+        if (size != count) {
+                error_msg_and_die("Short read");
+        }
+        return;
+}
+
+extern ssize_t xread_all_eof(int fd, void *buf, size_t count)
+{
+        ssize_t size;
+
+        size = xread(fd, buf, count);
+        if ((size != 0) && (size != count)) {
+                error_msg_and_die("Short read");
+        }
+        return(size);
+}
+
+extern unsigned char xread_char(int fd)
+{
+        char tmp;
+        
+        xread_all(fd, &tmp, 1);
+
+        return(tmp);    
+}
+
 /* Stupid gcc always includes its own builtin strlen()... */
 #undef strlen
 size_t xstrlen(const char *string)