Merge branch 'origin/master' (early part)

3 files changed, 398 insertions, 274 deletions

diff --git a/findutils/find.c b/findutils/find.c
index ca630b6c5..297081489 100644
--- a/findutils/find.c
+++ b/findutils/find.c
@@ -53,8 +53,10 @@
  * diff -u /tmp/std_find /tmp/bb_find && echo Identical
  */
 
+//applet:IF_FIND(APPLET_NOEXEC(find, find, _BB_DIR_USR_BIN, _BB_SUID_DROP, find))
+
 //kbuild:lib-$(CONFIG_FIND) += find.o
-//config:
+
 //config:config FIND
 //config:       bool "find"
 //config:       default y
@@ -1044,6 +1046,92 @@ static action*** parse_params(char **argv)
 #undef ALLOC_ACTION
 }
 
+//usage:#define find_trivial_usage
+//usage:       "[PATH]... [EXPRESSION]"
+//usage:#define find_full_usage "\n\n"
+//usage:       "Search for files. The default PATH is the current directory,\n"
+//usage:       "default EXPRESSION is '-print'\n"
+//usage:     "\nEXPRESSION may consist of:"
+//usage:     "\n        -follow         Follow symlinks"
+//usage:        IF_FEATURE_FIND_XDEV(
+//usage:     "\n        -xdev           Don't descend directories on other filesystems"
+//usage:        )
+//usage:        IF_FEATURE_FIND_MAXDEPTH(
+//usage:     "\n        -maxdepth N     Descend at most N levels. -maxdepth 0 applies"
+//usage:     "\n                        tests/actions to command line arguments only"
+//usage:        )
+//usage:     "\n        -mindepth N     Don't act on first N levels"
+//usage:     "\n        -name PATTERN   File name (w/o directory name) matches PATTERN"
+//usage:     "\n        -iname PATTERN  Case insensitive -name"
+//usage:        IF_FEATURE_FIND_PATH(
+//usage:     "\n        -path PATTERN   Path matches PATTERN"
+//usage:        )
+//usage:        IF_FEATURE_FIND_REGEX(
+//usage:     "\n        -regex PATTERN  Path matches regex PATTERN"
+//usage:        )
+//usage:        IF_FEATURE_FIND_TYPE(
+//usage:     "\n        -type X         File type is X (X is one of: f,d,l,b,c,...)"
+//usage:        )
+//usage:        IF_FEATURE_FIND_PERM(
+//usage:     "\n        -perm NNN       Permissions match any of (+NNN), all of (-NNN),"
+//usage:     "\n                        or exactly NNN"
+//usage:        )
+//usage:        IF_FEATURE_FIND_MTIME(
+//usage:     "\n        -mtime DAYS     Modified time is greater than (+N), less than (-N),"
+//usage:     "\n                        or exactly N days"
+//usage:        )
+//usage:        IF_FEATURE_FIND_MMIN(
+//usage:     "\n        -mmin MINS      Modified time is greater than (+N), less than (-N),"
+//usage:     "\n                        or exactly N minutes"
+//usage:        )
+//usage:        IF_FEATURE_FIND_NEWER(
+//usage:     "\n        -newer FILE     Modified time is more recent than FILE's"
+//usage:        )
+//usage:        IF_FEATURE_FIND_INUM(
+//usage:     "\n        -inum N         File has inode number N"
+//usage:        )
+//usage:        IF_FEATURE_FIND_USER(
+//usage:     "\n        -user NAME      File is owned by user NAME (numeric user ID allowed)"
+//usage:        )
+//usage:        IF_FEATURE_FIND_GROUP(
+//usage:     "\n        -group NAME     File belongs to group NAME (numeric group ID allowed)"
+//usage:        )
+//usage:        IF_FEATURE_FIND_DEPTH(
+//usage:     "\n        -depth          Process directory name after traversing it"
+//usage:        )
+//usage:        IF_FEATURE_FIND_SIZE(
+//usage:     "\n        -size N[bck]    File size is N (c:bytes,k:kbytes,b:512 bytes(def.))"
+//usage:     "\n                        +/-N: file size is bigger/smaller than N"
+//usage:        )
+//usage:        IF_FEATURE_FIND_LINKS(
+//usage:     "\n        -links N        Number of links is greater than (+N), less than (-N),"
+//usage:     "\n                        or exactly N"
+//usage:        )
+//usage:     "\n        -print          Print (default and assumed)"
+//usage:        IF_FEATURE_FIND_PRINT0(
+//usage:     "\n        -print0         Delimit output with null characters rather than"
+//usage:     "\n                        newlines"
+//usage:        )
+//usage:        IF_FEATURE_FIND_CONTEXT(
+//usage:     "\n        -context        File has specified security context"
+//usage:        )
+//usage:        IF_FEATURE_FIND_EXEC(
+//usage:     "\n        -exec CMD ARG ; Run CMD with all instances of {} replaced by the"
+//usage:     "\n                        matching files"
+//usage:        )
+//usage:        IF_FEATURE_FIND_PRUNE(
+//usage:     "\n        -prune          Stop traversing current subtree"
+//usage:        )
+//usage:        IF_FEATURE_FIND_DELETE(
+//usage:     "\n        -delete         Delete files, turns on -depth option"
+//usage:        )
+//usage:        IF_FEATURE_FIND_PAREN(
+//usage:     "\n        (EXPR)          Group an expression"
+//usage:        )
+//usage:
+//usage:#define find_example_usage
+//usage:       "$ find / -name passwd\n"
+//usage:       "/etc/passwd\n"
 
 int find_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int find_main(int argc UNUSED_PARAM, char **argv)
diff --git a/findutils/grep.c b/findutils/grep.c
index fedf12d8a..9eb5e5a1b 100644
--- a/findutils/grep.c
+++ b/findutils/grep.c
@@ -14,13 +14,16 @@
  * 2004,2006 (C) Vladimir Oleynik <dzo@simtreas.ru> -
  * correction "-e pattern1 -e pattern2" logic and more optimizations.
  * precompiled regex
- */
-/*
+ *
  * (C) 2006 Jac Goudsmit added -o option
  */
 
+//applet:IF_GREP(APPLET(grep, _BB_DIR_BIN, _BB_SUID_DROP))
+//applet:IF_FEATURE_GREP_EGREP_ALIAS(APPLET_ODDNAME(egrep, grep, _BB_DIR_BIN, _BB_SUID_DROP, egrep))
+//applet:IF_FEATURE_GREP_FGREP_ALIAS(APPLET_ODDNAME(fgrep, grep, _BB_DIR_BIN, _BB_SUID_DROP, fgrep))
+
 //kbuild:lib-$(CONFIG_GREP) += grep.o
-//config:
+
 //config:config GREP
 //config:       bool "grep"
 //config:       default y
@@ -57,17 +60,67 @@
 #include "libbb.h"
 #include "xregex.h"
 
+
 /* options */
+//usage:#define grep_trivial_usage
+//usage:       "[-HhnlLoqvsriw"
+//usage:       "F"
+//usage:        IF_FEATURE_GREP_EGREP_ALIAS("E")
+//usage:        IF_EXTRA_COMPAT("z")
+//usage:       "] [-m N] "
+//usage:        IF_FEATURE_GREP_CONTEXT("[-A/B/C N] ")
+//usage:       "PATTERN/-e PATTERN.../-f FILE [FILE]..."
+//usage:#define grep_full_usage "\n\n"
+//usage:       "Search for PATTERN in FILEs (or stdin)\n"
+//usage:     "\nOptions:"
+//usage:     "\n        -H      Add 'filename:' prefix"
+//usage:     "\n        -h      Do not add 'filename:' prefix"
+//usage:     "\n        -n      Add 'line_no:' prefix"
+//usage:     "\n        -l      Show only names of files that match"
+//usage:     "\n        -L      Show only names of files that don't match"
+//usage:     "\n        -c      Show only count of matching lines"
+//usage:     "\n        -o      Show only the matching part of line"
+//usage:     "\n        -q      Quiet. Return 0 if PATTERN is found, 1 otherwise"
+//usage:     "\n        -v      Select non-matching lines"
+//usage:     "\n        -s      Suppress open and read errors"
+//usage:     "\n        -r      Recurse"
+//usage:     "\n        -i      Ignore case"
+//usage:     "\n        -w      Match whole words only"
+//usage:     "\n        -F      PATTERN is a literal (not regexp)"
+//usage:        IF_FEATURE_GREP_EGREP_ALIAS(
+//usage:     "\n        -E      PATTERN is an extended regexp"
+//usage:        )
+//usage:        IF_EXTRA_COMPAT(
+//usage:     "\n        -z      Input is NUL terminated"
+//usage:        )
+//usage:     "\n        -m N    Match up to N times per file"
+//usage:        IF_FEATURE_GREP_CONTEXT(
+//usage:     "\n        -A N    Print N lines of trailing context"
+//usage:     "\n        -B N    Print N lines of leading context"
+//usage:     "\n        -C N    Same as '-A N -B N'"
+//usage:        )
+//usage:     "\n        -e PTRN Pattern to match"
+//usage:     "\n        -f FILE Read pattern from file"
+//usage:
+//usage:#define grep_example_usage
+//usage:       "$ grep root /etc/passwd\n"
+//usage:       "root:x:0:0:root:/root:/bin/bash\n"
+//usage:       "$ grep ^[rR]oo. /etc/passwd\n"
+//usage:       "root:x:0:0:root:/root:/bin/bash\n"
+//usage:
+//usage:#define egrep_trivial_usage NOUSAGE_STR
+//usage:#define egrep_full_usage ""
+//usage:#define fgrep_trivial_usage NOUSAGE_STR
+//usage:#define fgrep_full_usage ""
+
 #define OPTSTR_GREP \
         "lnqvscFiHhe:f:Lorm:w" \
         IF_FEATURE_GREP_CONTEXT("A:B:C:") \
         IF_FEATURE_GREP_EGREP_ALIAS("E") \
         IF_EXTRA_COMPAT("z") \
         "aI"
-
 /* ignored: -a "assume all files to be text" */
 /* ignored: -I "assume binary files have no matches" */
-
 enum {
         OPTBIT_l, /* list matched file names only */
         OPTBIT_n, /* print line# */
diff --git a/findutils/xargs.c b/findutils/xargs.c
index 9133b8f6c..46a62cbf1 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -1,7 +1,6 @@
 /* vi: set sw=4 ts=4: */
 /*
  * Mini xargs implementation for busybox
- * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"
  *
  * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
  *
@@ -14,11 +13,12 @@
  *
  * xargs is described in the Single Unix Specification v3 at
  * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
- *
  */
 
+//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, _BB_DIR_USR_BIN, _BB_SUID_DROP, xargs))
+
 //kbuild:lib-$(CONFIG_XARGS) += xargs.o
-//config:
+
 //config:config XARGS
 //config:       bool "xargs"
 //config:       default y
@@ -59,10 +59,6 @@
 //config:         are not special.
 
 #include "libbb.h"
-
-/* This is a NOEXEC applet. Be very careful! */
-
-
 /* COMPAT:  SYSV version defaults size (and has a max value of) to 470.
    We try to make it as large as possible. */
 #if !defined(ARG_MAX) && defined(_SC_ARG_MAX)
@@ -72,6 +68,12 @@
 # define ARG_MAX 470
 #endif
 
+/* This is a NOEXEC applet. Be very careful! */
+
+
+//#define dbg_msg(...) bb_error_msg(__VA_ARGS__)
+#define dbg_msg(...) ((void)0)
+
 
 #ifdef TEST
 # ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
@@ -88,26 +90,36 @@
 # endif
 #endif
 
+
+struct globals {
+        char **args;
+        const char *eof_str;
+        int idx;
+} FIX_ALIASING;
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { } while (0)
+
+
 /*
-   This function has special algorithm.
-   Don't use fork and include to main!
-*/
-static int xargs_exec(char **args)
+ * This function has special algorithm.
+ * Don't use fork and include to main!
+ */
+static int xargs_exec(void)
 {
         int status;
 
-        status = spawn_and_wait(args);
+        status = spawn_and_wait(G.args);
         if (status < 0) {
-                bb_simple_perror_msg(args[0]);
+                bb_simple_perror_msg(G.args[0]);
                 return errno == ENOENT ? 127 : 126;
         }
         if (status == 255) {
-                bb_error_msg("%s: exited with status 255; aborting", args[0]);
+                bb_error_msg("%s: exited with status 255; aborting", G.args[0]);
                 return 124;
         }
         if (status >= 0x180) {
                 bb_error_msg("%s: terminated by signal %d",
-                        args[0], status - 0x180);
+                        G.args[0], status - 0x180);
                 return 125;
         }
         if (status)
@@ -115,75 +127,75 @@ static int xargs_exec(char **args)
         return 0;
 }
 
+/* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space.
+ * "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13.
+ */
+#define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); })
 
-typedef struct xlist_t {
-        struct xlist_t *link;
-        size_t length;
-        char xstr[1];
-} xlist_t;
-
-static smallint eof_stdin_detected;
+static void store_param(char *s)
+{
+        /* Grow by 256 elements at once */
+        if (!(G.idx & 0xff)) { /* G.idx == N*256 */
+                /* Enlarge, make G.args[(N+1)*256 - 1] last valid idx */
+                G.args = xrealloc(G.args, sizeof(G.args[0]) * (G.idx + 0x100));
+        }
+        G.args[G.idx++] = s;
+}
 
-#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
-#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \
-                    || (c) == '\f' || (c) == '\v')
+/* process[0]_stdin:
+ * Read characters into buf[n_max_chars+1], and when parameter delimiter
+ * is seen, store the address of a new parameter to args[].
+ * If reading discovers that last chars do not form the complete
+ * parameter, the pointer to the first such "tail character" is returned.
+ * (buf has extra byte at the end to accomodate terminating NUL
+ * of "tail characters" string).
+ * Otherwise, the returned pointer points to NUL byte.
+ * On entry, buf[] may contain some "seed chars" which are to become
+ * the beginning of the first parameter.
+ */
 
 #if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
-static xlist_t *process_stdin(xlist_t *list_arg,
-        const char *eof_str, size_t mc, char *buf)
+static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
 {
 #define NORM      0
 #define QUOTE     1
 #define BACKSLASH 2
 #define SPACE     4
-
-        char *s = NULL;         /* start word */
-        char *p = NULL;         /* pointer to end word */
-        char q = '\0';          /* quote char */
+        char q = '\0';             /* quote char */
         char state = NORM;
-        char eof_str_detected = 0;
-        size_t line_l = 0;      /* size loaded args line */
-        int c;                  /* current char */
-        xlist_t *cur;
-        xlist_t *prev;
+        char *s = buf;             /* start of the word */
+        char *p = s + strlen(buf); /* end of the word */
 
-        prev = cur = list_arg;
-        while (1) {
-                if (!cur) break;
-                prev = cur;
-                line_l += cur->length;
-                cur = cur->link;
-        }
+        buf += n_max_chars;        /* past buffer's end */
+
+        /* "goto ret" is used instead of "break" to make control flow
+         * more obvious: */
 
-        while (!eof_stdin_detected) {
-                c = getchar();
+        while (1) {
+                int c = getchar();
                 if (c == EOF) {
-                        eof_stdin_detected = 1;
-                        if (s)
-                                goto unexpected_eof;
-                        break;
+                        if (p != s)
+                                goto close_word;
+                        goto ret;
                 }
-                if (eof_str_detected)
-                        continue;
                 if (state == BACKSLASH) {
                         state = NORM;
                         goto set;
-                } else if (state == QUOTE) {
+                }
+                if (state == QUOTE) {
                         if (c != q)
                                 goto set;
                         q = '\0';
                         state = NORM;
                 } else { /* if (state == NORM) */
                         if (ISSPACE(c)) {
-                                if (s) {
- unexpected_eof:
+                                if (p != s) {
+ close_word:
                                         state = SPACE;
                                         c = '\0';
                                         goto set;
                                 }
                         } else {
-                                if (s == NULL)
-                                        s = p = buf;
                                 if (c == '\\') {
                                         state = BACKSLASH;
                                 } else if (c == '\'' || c == '"') {
@@ -191,8 +203,6 @@ static xlist_t *process_stdin(xlist_t *list_arg,
                                         state = QUOTE;
                                 } else {
  set:
-                                        if ((size_t)(p - buf) >= mc)
-                                                bb_error_msg_and_die("argument line too long");
                                         *p++ = c;
                                 }
                         }
@@ -202,105 +212,122 @@ static xlist_t *process_stdin(xlist_t *list_arg,
                                 bb_error_msg_and_die("unmatched %s quote",
                                         q == '\'' ? "single" : "double");
                         }
-                        /* word loaded */
-                        if (eof_str) {
-                                eof_str_detected = (strcmp(s, eof_str) == 0);
-                        }
-                        if (!eof_str_detected) {
-                                size_t length = (p - buf);
-                                /* Dont xzalloc - it can be quite big */
-                                cur = xmalloc(offsetof(xlist_t, xstr) + length);
-                                cur->link = NULL;
-                                cur->length = length;
-                                memcpy(cur->xstr, s, length);
-                                if (prev == NULL) {
-                                        list_arg = cur;
-                                } else {
-                                        prev->link = cur;
-                                }
-                                prev = cur;
-                                line_l += length;
-                                if (line_l > mc) {
-                                        /* stop memory usage :-) */
-                                        break;
+                        /* A full word is loaded */
+                        if (G.eof_str) {
+                                if (strcmp(s, G.eof_str) == 0) {
+                                        while (getchar() != EOF)
+                                                continue;
+                                        p = s;
+                                        goto ret;
                                 }
                         }
-                        s = NULL;
+                        store_param(s);
+                        dbg_msg("args[]:'%s'", s);
+                        s = p;
+                        n_max_arg--;
+                        if (n_max_arg == 0) {
+                                goto ret;
+                        }
                         state = NORM;
                 }
+                if (p == buf) {
+                        goto ret;
+                }
         }
-        return list_arg;
+ ret:
+        *p = '\0';
+        /* store_param(NULL) - caller will do it */
+        dbg_msg("return:'%s'", s);
+        return s;
 }
 #else
 /* The variant does not support single quotes, double quotes or backslash */
-static xlist_t *process_stdin(xlist_t *list_arg,
-                const char *eof_str, size_t mc, char *buf)
+static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
 {
+        char *s = buf;             /* start of the word */
+        char *p = s + strlen(buf); /* end of the word */
 
-        int c;                  /* current char */
-        char eof_str_detected = 0;
-        char *s = NULL;         /* start word */
-        char *p = NULL;         /* pointer to end word */
-        size_t line_l = 0;      /* size loaded args line */
-        xlist_t *cur;
-        xlist_t *prev;
+        buf += n_max_chars;        /* past buffer's end */
 
-        prev = cur = list_arg;
         while (1) {
-                if (!cur) break;
-                prev = cur;
-                line_l += cur->length;
-                cur = cur->link;
-        }
-
-        while (!eof_stdin_detected) {
-                c = getchar();
+                int c = getchar();
                 if (c == EOF) {
-                        eof_stdin_detected = 1;
+                        if (p == s)
+                                goto ret;
                 }
-                if (eof_str_detected)
-                        continue;
                 if (c == EOF || ISSPACE(c)) {
-                        if (s == NULL)
+                        if (p == s)
                                 continue;
                         c = EOF;
                 }
-                if (s == NULL)
-                        s = p = buf;
-                if ((size_t)(p - buf) >= mc)
-                        bb_error_msg_and_die("argument line too long");
                 *p++ = (c == EOF ? '\0' : c);
                 if (c == EOF) { /* word's delimiter or EOF detected */
-                        /* word loaded */
-                        if (eof_str) {
-                                eof_str_detected = (strcmp(s, eof_str) == 0);
-                        }
-                        if (!eof_str_detected) {
-                                size_t length = (p - buf);
-                                /* Dont xzalloc - it can be quite big */
-                                cur = xmalloc(offsetof(xlist_t, xstr) + length);
-                                cur->link = NULL;
-                                cur->length = length;
-                                memcpy(cur->xstr, s, length);
-                                if (prev == NULL) {
-                                        list_arg = cur;
-                                } else {
-                                        prev->link = cur;
+                        /* A full word is loaded */
+                        if (G.eof_str) {
+                                if (strcmp(s, G.eof_str) == 0) {
+                                        while (getchar() != EOF)
+                                                continue;
+                                        p = s;
+                                        goto ret;
                                 }
-                                prev = cur;
-                                line_l += length;
-                                if (line_l > mc) {
-                                        /* stop memory usage :-) */
-                                        break;
-                                }
-                                s = NULL;
                         }
+                        store_param(s);
+                        dbg_msg("args[]:'%s'", s);
+                        s = p;
+                        n_max_arg--;
+                        if (n_max_arg == 0) {
+                                goto ret;
+                        }
+                }
+                if (p == buf) {
+                        goto ret;
                 }
         }
-        return list_arg;
+ ret:
+        *p = '\0';
+        /* store_param(NULL) - caller will do it */
+        dbg_msg("return:'%s'", s);
+        return s;
 }
 #endif /* FEATURE_XARGS_SUPPORT_QUOTES */
 
+#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
+static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf)
+{
+        char *s = buf;             /* start of the word */
+        char *p = s + strlen(buf); /* end of the word */
+
+        buf += n_max_chars;        /* past buffer's end */
+
+        while (1) {
+                int c = getchar();
+                if (c == EOF) {
+                        if (p == s)
+                                goto ret;
+                        c = '\0';
+                }
+                *p++ = c;
+                if (c == '\0') {   /* word's delimiter or EOF detected */
+                        /* A full word is loaded */
+                        store_param(s);
+                        dbg_msg("args[]:'%s'", s);
+                        s = p;
+                        n_max_arg--;
+                        if (n_max_arg == 0) {
+                                goto ret;
+                        }
+                }
+                if (p == buf) {
+                        goto ret;
+                }
+        }
+ ret:
+        *p = '\0';
+        /* store_param(NULL) - caller will do it */
+        dbg_msg("return:'%s'", s);
+        return s;
+}
+#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
 
 #if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
 /* Prompt the user for a response, and
@@ -322,65 +349,30 @@ static int xargs_ask_confirmation(void)
 }
 #else
 # define xargs_ask_confirmation() 1
-#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */
-
-#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
-static xlist_t *process0_stdin(xlist_t *list_arg,
-                const char *eof_str UNUSED_PARAM, size_t mc, char *buf)
-{
-        int c;                  /* current char */
-        char *s = NULL;         /* start word */
-        char *p = NULL;         /* pointer to end word */
-        size_t line_l = 0;      /* size loaded args line */
-        xlist_t *cur;
-        xlist_t *prev;
-
-        prev = cur = list_arg;
-        while (1) {
-                if (!cur) break;
-                prev = cur;
-                line_l += cur->length;
-                cur = cur->link;
-        }
+#endif
 
-        while (!eof_stdin_detected) {
-                c = getchar();
-                if (c == EOF) {
-                        eof_stdin_detected = 1;
-                        if (s == NULL)
-                                break;
-                        c = '\0';
-                }
-                if (s == NULL)
-                        s = p = buf;
-                if ((size_t)(p - buf) >= mc)
-                        bb_error_msg_and_die("argument line too long");
-                *p++ = c;
-                if (c == '\0') {   /* word's delimiter or EOF detected */
-                        /* word loaded */
-                        size_t length = (p - buf);
-                        /* Dont xzalloc - it can be quite big */
-                        cur = xmalloc(offsetof(xlist_t, xstr) + length);
-                        cur->link = NULL;
-                        cur->length = length;
-                        memcpy(cur->xstr, s, length);
-                        if (prev == NULL) {
-                                list_arg = cur;
-                        } else {
-                                prev->link = cur;
-                        }
-                        prev = cur;
-                        line_l += length;
-                        if (line_l > mc) {
-                                /* stop memory usage :-) */
-                                break;
-                        }
-                        s = NULL;
-                }
-        }
-        return list_arg;
-}
-#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
+//usage:#define xargs_trivial_usage
+//usage:       "[OPTIONS] [PROG ARGS]"
+//usage:#define xargs_full_usage "\n\n"
+//usage:       "Run PROG on every item given by stdin\n"
+//usage:     "\nOptions:"
+//usage:        IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(
+//usage:     "\n        -p      Ask user whether to run each command"
+//usage:        )
+//usage:     "\n        -r      Don't run command if input is empty"
+//usage:        IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(
+//usage:     "\n        -0      Input is separated by NUL characters"
+//usage:        )
+//usage:     "\n        -t      Print the command on stderr before execution"
+//usage:     "\n        -e[STR] STR stops input processing"
+//usage:     "\n        -n N    Pass no more than N args to PROG"
+//usage:     "\n        -s N    Pass command line of no more than N bytes"
+//usage:        IF_FEATURE_XARGS_SUPPORT_TERMOPT(
+//usage:     "\n        -x      Exit if size is exceeded"
+//usage:        )
+//usage:#define xargs_example_usage
+//usage:       "$ ls | xargs gzip\n"
+//usage:       "$ find . -name '*.c' -print | xargs rm\n"
 
 /* Correct regardless of combination of CONFIG_xxx */
 enum {
@@ -412,44 +404,42 @@ enum {
 int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int xargs_main(int argc, char **argv)
 {
-        char **args;
-        int i, n;
-        xlist_t *list = NULL;
-        xlist_t *cur;
+        int i;
         int child_error = 0;
-        char *max_args, *max_chars;
-        int n_max_arg;
-        const char *eof_str = NULL;
+        char *max_args;
+        char *max_chars;
+        char *buf;
         unsigned opt;
-        size_t n_max_chars;
+        int n_max_chars;
+        int n_max_arg;
 #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
-        xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin;
+        char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin;
 #else
 #define read_args process_stdin
 #endif
 
-        opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str);
+        INIT_G();
+
+        G.eof_str = NULL;
+        opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str);
 
         /* -E ""? You may wonder why not just omit -E?
          * This is used for portability:
          * old xargs was using "_" as default for -E / -e */
-        if ((opt & OPT_EOF_STRING1) && eof_str[0] == '\0')
-                eof_str = NULL;
+        if ((opt & OPT_EOF_STRING1) && G.eof_str[0] == '\0')
+                G.eof_str = NULL;
 
         if (opt & OPT_ZEROTERM)
                 IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
 
         argv += optind;
         argc -= optind;
-        if (!argc) {
+        if (!argv[0]) {
                 /* default behavior is to echo all the filenames */
-                *argv = (char*)"echo";
+                *--argv = (char*)"echo";
                 argc++;
         }
 
-        n_max_chars = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */
-        if (n_max_chars < 4*1024); /* paranoia */
-                n_max_chars = LONG_MAX;
         /* The Open Group Base Specifications Issue 6:
          * "The xargs utility shall limit the command line length such that
          * when the command line is invoked, the combined argument
@@ -457,101 +447,94 @@ int xargs_main(int argc, char **argv)
          * in the System Interfaces volume of IEEE Std 1003.1-2001)
          * shall not exceed {ARG_MAX}-2048 bytes".
          */
+        n_max_chars = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */
+        if (n_max_chars < 4*1024); /* paranoia */
+                n_max_chars = 4*1024;
         n_max_chars -= 2048;
         /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
-         * have it at 1 meg).  Things will work fine with a large ARG_MAX but it
-         * will probably hurt the system more than it needs to; an array of this
-         * size is allocated.
+         * have it at 1 meg).  Things will work fine with a large ARG_MAX
+         * but it will probably hurt the system more than it needs to;
+         * an array of this size is allocated.
          */
         if (n_max_chars > 20 * 1024)
                 n_max_chars = 20 * 1024;
 
         if (opt & OPT_UPTO_SIZE) {
                 size_t n_chars = 0;
-                n_max_chars = xatoul_range(max_chars, 1, n_max_chars);
-                for (i = 0; i < argc; i++) {
-                        n_chars += strlen(*argv) + 1;
+                n_max_chars = xatou_range(max_chars, 1, INT_MAX);
+                for (i = 0; argv[i]; i++) {
+                        n_chars += strlen(argv[i]) + 1;
                 }
-                if (n_max_chars <= n_chars) {
+                n_max_chars -= n_chars;
+                if (n_max_chars <= 0) {
                         bb_error_msg_and_die("can't fit single argument within argument list size limit");
                 }
-                n_max_chars -= n_chars;
         }
-        max_chars = xmalloc(n_max_chars);
 
+        buf = xzalloc(n_max_chars + 1);
+
+        n_max_arg = n_max_chars;
         if (opt & OPT_UPTO_NUMBER) {
-                n_max_arg = xatoul_range(max_args, 1, INT_MAX);
-        } else {
-                n_max_arg = n_max_chars;
+                n_max_arg = xatou_range(max_args, 1, INT_MAX);
         }
 
-        while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL ||
-                !(opt & OPT_NO_EMPTY))
-        {
-                size_t n_chars = 0;
-                opt |= OPT_NO_EMPTY;
-                n = 0;
-#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
-                for (cur = list; cur;) {
-                        n_chars += cur->length;
-                        n++;
-                        cur = cur->link;
-                        if (n_chars > n_max_chars || (n == n_max_arg && cur)) {
-                                if (opt & OPT_TERMINATE)
-                                        bb_error_msg_and_die("argument list too long");
-                                break;
-                        }
-                }
-#else
-                for (cur = list; cur; cur = cur->link) {
-                        n_chars += cur->length;
-                        n++;
-                        if (n_chars > n_max_chars || n == n_max_arg) {
+        /* Allocate pointers for execvp */
+        /* We can statically allocate (argc + n_max_arg + 1) elements
+         * and do not bother with resizing args[], but on 64-bit machines
+         * this results in args[] vector which is ~8 times bigger
+         * than n_max_chars! That is, with n_max_chars == 20k,
+         * args[] will take 160k (!), which will most likely be
+         * almost entirely unused.
+         */
+        /* See store_param() for matching 256-step growth logic */
+        G.args = xmalloc(sizeof(G.args[0]) * ((argc + 0xff) & ~0xff));
+
+        /* Store the command to be executed, part 1 */
+        for (i = 0; argv[i]; i++)
+                G.args[i] = argv[i];
+
+        while (1) {
+                char *rem;
+
+                G.idx = argc;
+                rem = read_args(n_max_chars, n_max_arg, buf);
+                store_param(NULL);
+
+                if (!G.args[argc]) {
+                        if (*rem != '\0')
+                                bb_error_msg_and_die("argument line too long");
+                        if (opt & OPT_NO_EMPTY)
                                 break;
-                        }
-                }
-#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */
-
-                /* allocate pointers for execvp:
-                   argc*arg, n*arg from stdin, NULL */
-                args = xzalloc((n + argc + 1) * sizeof(char *));
-
-                /* store the command to be executed
-                   (taken from the command line) */
-                for (i = 0; i < argc; i++)
-                        args[i] = argv[i];
-                /* (taken from stdin) */
-                for (cur = list; n; cur = cur->link) {
-                        args[i++] = cur->xstr;
-                        n--;
                 }
+                opt |= OPT_NO_EMPTY;
 
                 if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
+                        const char *fmt = " %s" + 1;
+                        char **args = G.args;
                         for (i = 0; args[i]; i++) {
-                                if (i)
-                                        bb_putchar_stderr(' ');
-                                fputs(args[i], stderr);
+                                fprintf(stderr, fmt, args[i]);
+                                fmt = " %s";
                         }
                         if (!(opt & OPT_INTERACTIVE))
                                 bb_putchar_stderr('\n');
                 }
+
                 if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
-                        child_error = xargs_exec(args);
+                        child_error = xargs_exec();
                 }
 
-                /* clean up */
-                for (i = argc; args[i]; i++) {
-                        cur = list;
-                        list = list->link;
-                        free(cur);
-                }
-                free(args);
                 if (child_error > 0 && child_error != 123) {
                         break;
                 }
+
+                overlapping_strcpy(buf, rem);
         } /* while */
-        if (ENABLE_FEATURE_CLEAN_UP)
-                free(max_chars);
+
+        if (ENABLE_FEATURE_CLEAN_UP) {
+                free(G.args);
+                free(buf);
+        }
+
         return child_error;
 }