Support for tar -z option for uncompressing only

6 files changed, 163 insertions, 48 deletions

diff --git a/Changelog b/Changelog
index 2c6fbabd9..6a1612876 100644
--- a/Changelog
+++ b/Changelog
@@ -1,5 +1,7 @@
 0.48
 
+        * Glenn McGrath -- tar now supports uncompressing tar files,
+            define BB_FEATURE_TAR_GZIP to use the -z option.
         * Matt Kraai -- fix all usage of TRUE and FALSE so all apps now
             return EXIT_SUCCESS or EXIT_FAILURE to the system.
             Now TRUE and FALSE are set to the C standard where TRUE=1.
diff --git a/Config.h b/Config.h
index 50f9e3ac7..d95942a65 100644
--- a/Config.h
+++ b/Config.h
@@ -225,6 +225,9 @@
 // Enable support for "--exclude" and "-X" for excluding files
 #define BB_FEATURE_TAR_EXCLUDE
 //
+// Enable support for tar -z option (currently only works for inflating)
+#define BB_FEATURE_TAR_GZIP 
+//
 //// Enable reverse sort
 #define BB_FEATURE_SORT_REVERSE
 //
@@ -324,6 +327,12 @@
 #endif
 #endif
 //
+#ifdef BB_FEATURE_TAR_GZIP
+#ifndef BB_GUNZIP
+#define BB_GUNZIP
+#endif
+#endif
+//
 #if defined BB_MOUNT && defined BB_FEATURE_NFSMOUNT
 #define BB_NFSMOUNT
 #endif
diff --git a/archival/gunzip.c b/archival/gunzip.c
index 48db7cfd7..8558573ba 100644
--- a/archival/gunzip.c
+++ b/archival/gunzip.c
@@ -1084,7 +1084,7 @@ int inflate()
  *   the compressed data, from offsets inptr to insize-1 included.
  *   The magic header has already been checked. The output buffer is cleared.
  */
-int unzip(in, out)
+extern int unzip(in, out)
 int in, out;                                    /* input and output file descriptors */
 {
         int ext_header = 0;                             /* set if extended local header */
@@ -1179,7 +1179,7 @@ void clear_bufs(void)
 /* ===========================================================================
  * Initialize gunzip buffers and signals
  */
-static int gunzip_init()
+extern int gunzip_init()
 {
         foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
         if (foreground) {
diff --git a/archival/tar.c b/archival/tar.c
index cc7ba3b80..8c2650e2b 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -52,6 +52,11 @@
 #include <sys/sysmacros.h>
 #include <getopt.h>
 
+#ifdef BB_FEATURE_TAR_GZIP
+extern int unzip(int in, int out);
+extern int gunzip_init();
+#endif
+
 /* Tar file constants  */
 #ifndef MAJOR
 #define MAJOR(dev) (((dev)>>8)&0xff)
@@ -129,29 +134,64 @@ struct TarInfo
 typedef struct TarInfo TarInfo;
 
 /* Local procedures to restore files from a tar file.  */
-static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
+static int readTarFile(int tarFd, int extractFlag, int listFlag, 
                 int tostdoutFlag, int verboseFlag, char** extractList,
                 char** excludeList);
 
-
-
 #ifdef BB_FEATURE_TAR_CREATE
 /* Local procedures to save files into a tar file.  */
 static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
                 char** excludeList);
 #endif
 
+#ifdef BB_FEATURE_TAR_GZIP
+/* Signal handler for when child gzip process dies...  */
+void child_died()
+{
+        fflush(stdout);
+        fflush(stderr);
+        exit(EXIT_FAILURE);
+}
+
+static int tar_unzip_init(int tarFd)
+{
+        int child_pid;
+        static int unzip_pipe[2];
+        /* Cope if child dies... Otherwise we block forever in read()... */
+        signal(SIGCHLD, child_died);
+
+        if (pipe(unzip_pipe)!=0)
+                error_msg_and_die("pipe error\n");
+                        
+        if ( (child_pid = fork()) == -1)
+                error_msg_and_die("fork failure\n");
+
+        if (child_pid==0) {
+                /* child process */
+                gunzip_init();
+                unzip(tarFd, unzip_pipe[1]);
+                exit(EXIT_SUCCESS);
+        }
+        else
+                /* return fd of uncompressed data to parent process */
+                return(unzip_pipe[0]);
+}
+#endif
+
 extern int tar_main(int argc, char **argv)
 {
         char** excludeList=NULL;
         char** extractList=NULL;
+        const char *tarName="-";
 #if defined BB_FEATURE_TAR_EXCLUDE
         int excludeListSize=0;
-        char *excludeFileName ="-";
-        FILE *fileList;
-        char file[256];
+        char *excludeFileName ="-";
+        FILE *fileList;
+        char file[256];
+#endif
+#if defined BB_FEATURE_TAR_GZIP
+        int unzipFlag    = FALSE;
 #endif
-        const char *tarName="-";
         int listFlag     = FALSE;
         int extractFlag  = FALSE;
         int createFlag   = FALSE;
@@ -160,7 +200,6 @@ extern int tar_main(int argc, char **argv)
         int status       = FALSE;
         int firstOpt     = TRUE;
         int stopIt;
-                                                                                                                                                   
 
         if (argc <= 1)
                 usage(tar_usage);
@@ -185,6 +224,11 @@ extern int tar_main(int argc, char **argv)
                                                 goto flagError;
                                         listFlag = TRUE;
                                         break;
+#ifdef BB_FEATURE_TAR_GZIP
+                                case 'z':
+                                        unzipFlag = TRUE;
+                                        break;
+#endif
                                 case 'v':
                                         verboseFlag = TRUE;
                                         break;
@@ -255,13 +299,31 @@ extern int tar_main(int argc, char **argv)
 #ifndef BB_FEATURE_TAR_CREATE
                 error_msg_and_die( "This version of tar was not compiled with tar creation support.\n");
 #else
+#ifdef BB_FEATURE_TAR_GZIP
+                if (unzipFlag==TRUE)
+                        error_msg_and_die("Creation of compressed not internally support by tar, pipe to busybox gunzip\n");
+#endif
                 status = writeTarFile(tarName, verboseFlag, argv, excludeList);
 #endif
         }
         if (listFlag == TRUE || extractFlag == TRUE) {
+                int tarFd;
                 if (*argv)
                         extractList = argv;
-                status = readTarFile(tarName, extractFlag, listFlag, tostdoutFlag,
+                /* Open the tar file for reading.  */
+                if (!strcmp(tarName, "-"))
+                        tarFd = fileno(stdin);
+                else
+                        tarFd = open(tarName, O_RDONLY);
+                if (tarFd < 0)
+                        error_msg_and_die( "Error opening '%s': %s\n", tarName, strerror(errno));
+
+#ifdef BB_FEATURE_TAR_GZIP      
+                /* unzip tarFd in a seperate process */
+                if (unzipFlag == TRUE)
+                        tarFd = tar_unzip_init(tarFd);
+#endif                  
+                status = readTarFile(tarFd, extractFlag, listFlag, tostdoutFlag,
                                         verboseFlag, extractList, excludeList);
         }
 
@@ -521,27 +583,17 @@ readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
  * Read a tar file and extract or list the specified files within it.
  * If the list is empty than all files are extracted or listed.
  */
-static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
+extern int readTarFile(int tarFd, int extractFlag, int listFlag, 
                 int tostdoutFlag, int verboseFlag, char** extractList,
                 char** excludeList)
 {
-        int status, tarFd=-1;
+        int status;
         int errorFlag=FALSE;
         int skipNextHeaderFlag=FALSE;
         TarHeader rawHeader;
         TarInfo header;
         char** tmpList;
 
-        /* Open the tar file for reading.  */
-        if (!strcmp(tarName, "-"))
-                tarFd = fileno(stdin);
-        else
-                tarFd = open(tarName, O_RDONLY);
-        if (tarFd < 0) {
-                error_msg( "Error opening '%s': %s\n", tarName, strerror(errno));
-                return ( FALSE);
-        }
-
         /* Set the umask for this process so it doesn't 
          * screw up permission setting for us later. */
         umask(0);
@@ -739,7 +791,7 @@ static int readTarFile(const char* tarName, int extractFlag, int listFlag,
         close(tarFd);
         if (status > 0) {
                 /* Bummer - we read a partial header */
-                error_msg( "Error reading '%s': %s\n", tarName, strerror(errno));
+                error_msg( "Error reading tar file: %s\n", strerror(errno));
                 return ( FALSE);
         }
         else if (errorFlag==TRUE) {
diff --git a/gunzip.c b/gunzip.c
index 48db7cfd7..8558573ba 100644
--- a/gunzip.c
+++ b/gunzip.c
@@ -1084,7 +1084,7 @@ int inflate()
  *   the compressed data, from offsets inptr to insize-1 included.
  *   The magic header has already been checked. The output buffer is cleared.
  */
-int unzip(in, out)
+extern int unzip(in, out)
 int in, out;                                    /* input and output file descriptors */
 {
         int ext_header = 0;                             /* set if extended local header */
@@ -1179,7 +1179,7 @@ void clear_bufs(void)
 /* ===========================================================================
  * Initialize gunzip buffers and signals
  */
-static int gunzip_init()
+extern int gunzip_init()
 {
         foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
         if (foreground) {
diff --git a/tar.c b/tar.c
index cc7ba3b80..8c2650e2b 100644
--- a/tar.c
+++ b/tar.c
@@ -52,6 +52,11 @@
 #include <sys/sysmacros.h>
 #include <getopt.h>
 
+#ifdef BB_FEATURE_TAR_GZIP
+extern int unzip(int in, int out);
+extern int gunzip_init();
+#endif
+
 /* Tar file constants  */
 #ifndef MAJOR
 #define MAJOR(dev) (((dev)>>8)&0xff)
@@ -129,29 +134,64 @@ struct TarInfo
 typedef struct TarInfo TarInfo;
 
 /* Local procedures to restore files from a tar file.  */
-static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
+static int readTarFile(int tarFd, int extractFlag, int listFlag, 
                 int tostdoutFlag, int verboseFlag, char** extractList,
                 char** excludeList);
 
-
-
 #ifdef BB_FEATURE_TAR_CREATE
 /* Local procedures to save files into a tar file.  */
 static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
                 char** excludeList);
 #endif
 
+#ifdef BB_FEATURE_TAR_GZIP
+/* Signal handler for when child gzip process dies...  */
+void child_died()
+{
+        fflush(stdout);
+        fflush(stderr);
+        exit(EXIT_FAILURE);
+}
+
+static int tar_unzip_init(int tarFd)
+{
+        int child_pid;
+        static int unzip_pipe[2];
+        /* Cope if child dies... Otherwise we block forever in read()... */
+        signal(SIGCHLD, child_died);
+
+        if (pipe(unzip_pipe)!=0)
+                error_msg_and_die("pipe error\n");
+                        
+        if ( (child_pid = fork()) == -1)
+                error_msg_and_die("fork failure\n");
+
+        if (child_pid==0) {
+                /* child process */
+                gunzip_init();
+                unzip(tarFd, unzip_pipe[1]);
+                exit(EXIT_SUCCESS);
+        }
+        else
+                /* return fd of uncompressed data to parent process */
+                return(unzip_pipe[0]);
+}
+#endif
+
 extern int tar_main(int argc, char **argv)
 {
         char** excludeList=NULL;
         char** extractList=NULL;
+        const char *tarName="-";
 #if defined BB_FEATURE_TAR_EXCLUDE
         int excludeListSize=0;
-        char *excludeFileName ="-";
-        FILE *fileList;
-        char file[256];
+        char *excludeFileName ="-";
+        FILE *fileList;
+        char file[256];
+#endif
+#if defined BB_FEATURE_TAR_GZIP
+        int unzipFlag    = FALSE;
 #endif
-        const char *tarName="-";
         int listFlag     = FALSE;
         int extractFlag  = FALSE;
         int createFlag   = FALSE;
@@ -160,7 +200,6 @@ extern int tar_main(int argc, char **argv)
         int status       = FALSE;
         int firstOpt     = TRUE;
         int stopIt;
-                                                                                                                                                   
 
         if (argc <= 1)
                 usage(tar_usage);
@@ -185,6 +224,11 @@ extern int tar_main(int argc, char **argv)
                                                 goto flagError;
                                         listFlag = TRUE;
                                         break;
+#ifdef BB_FEATURE_TAR_GZIP
+                                case 'z':
+                                        unzipFlag = TRUE;
+                                        break;
+#endif
                                 case 'v':
                                         verboseFlag = TRUE;
                                         break;
@@ -255,13 +299,31 @@ extern int tar_main(int argc, char **argv)
 #ifndef BB_FEATURE_TAR_CREATE
                 error_msg_and_die( "This version of tar was not compiled with tar creation support.\n");
 #else
+#ifdef BB_FEATURE_TAR_GZIP
+                if (unzipFlag==TRUE)
+                        error_msg_and_die("Creation of compressed not internally support by tar, pipe to busybox gunzip\n");
+#endif
                 status = writeTarFile(tarName, verboseFlag, argv, excludeList);
 #endif
         }
         if (listFlag == TRUE || extractFlag == TRUE) {
+                int tarFd;
                 if (*argv)
                         extractList = argv;
-                status = readTarFile(tarName, extractFlag, listFlag, tostdoutFlag,
+                /* Open the tar file for reading.  */
+                if (!strcmp(tarName, "-"))
+                        tarFd = fileno(stdin);
+                else
+                        tarFd = open(tarName, O_RDONLY);
+                if (tarFd < 0)
+                        error_msg_and_die( "Error opening '%s': %s\n", tarName, strerror(errno));
+
+#ifdef BB_FEATURE_TAR_GZIP      
+                /* unzip tarFd in a seperate process */
+                if (unzipFlag == TRUE)
+                        tarFd = tar_unzip_init(tarFd);
+#endif                  
+                status = readTarFile(tarFd, extractFlag, listFlag, tostdoutFlag,
                                         verboseFlag, extractList, excludeList);
         }
 
@@ -521,27 +583,17 @@ readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
  * Read a tar file and extract or list the specified files within it.
  * If the list is empty than all files are extracted or listed.
  */
-static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
+extern int readTarFile(int tarFd, int extractFlag, int listFlag, 
                 int tostdoutFlag, int verboseFlag, char** extractList,
                 char** excludeList)
 {
-        int status, tarFd=-1;
+        int status;
         int errorFlag=FALSE;
         int skipNextHeaderFlag=FALSE;
         TarHeader rawHeader;
         TarInfo header;
         char** tmpList;
 
-        /* Open the tar file for reading.  */
-        if (!strcmp(tarName, "-"))
-                tarFd = fileno(stdin);
-        else
-                tarFd = open(tarName, O_RDONLY);
-        if (tarFd < 0) {
-                error_msg( "Error opening '%s': %s\n", tarName, strerror(errno));
-                return ( FALSE);
-        }
-
         /* Set the umask for this process so it doesn't 
          * screw up permission setting for us later. */
         umask(0);
@@ -739,7 +791,7 @@ static int readTarFile(const char* tarName, int extractFlag, int listFlag,
         close(tarFd);
         if (status > 0) {
                 /* Bummer - we read a partial header */
-                error_msg( "Error reading '%s': %s\n", tarName, strerror(errno));
+                error_msg( "Error reading tar file: %s\n", strerror(errno));
                 return ( FALSE);
         }
         else if (errorFlag==TRUE) {