/* minigzip.c -- simulate gzip using the zlib compression library

  * Copyright (C) 1995-1998 Jean-loup Gailly.

  * For conditions of distribution and use, see copyright notice in zlib.h 

  */

 /*

  * minigzip is a minimal implementation of the gzip utility. This is

  * only an example of using zlib and isn't meant to replace the

  * full-featured gzip. No attempt is made to deal with file systems

  * limiting names to 14 or 8+3 characters, etc... Error checking is

  * very limited. So use minigzip only for testing; use gzip for the

  * real thing. On MSDOS, use only on file names without extension

  * or in pipe mode.

  */

 /* @(#) $Id$ */

 #include <stdio.h>

 #include "zlib.h"

 #ifdef STDC

 #  include <string.h>

 #  include <stdlib.h>

 #else

    extern void exit  OF((int));

 #endif

 #ifdef USE_MMAP

 #  include <sys/types.h>

 #  include <sys/mman.h>

 #  include <sys/stat.h>

 #endif

 #if defined(MSDOS) || defined(OS2) || defined(WIN32)

 #  include <fcntl.h>

 #  include <io.h>

 #  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)

 #else

 #  define SET_BINARY_MODE(file)

 #endif

 #ifdef VMS

 #  define unlink delete

 #  define GZ_SUFFIX "-gz"

 #endif

 #ifdef RISCOS

 #  define unlink remove

 #  define GZ_SUFFIX "-gz"

 #  define fileno(file) file->__file

 #endif

 #if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os

 #  include <unix.h> /* for fileno */

 #endif

 #ifndef WIN32 /* unlink already in stdio.h for WIN32 */

   extern int unlink OF((const char *));

 #endif

 #ifndef GZ_SUFFIX

 #  define GZ_SUFFIX ".gz"

 #endif

 #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)

 #define BUFLEN      16384

 #define MAX_NAME_LEN 1024

 #ifdef MAXSEG_64K

 #  define local static

    /* Needed for systems with limitation on stack size. */

 #else

 #  define local

 #endif

 char *prog;

 void error            OF((const char *msg));

 void gz_compress      OF((FILE   *in, gzFile out));

 #ifdef USE_MMAP

 int  gz_compress_mmap OF((FILE   *in, gzFile out));

 #endif

 void gz_uncompress    OF((gzFile in, FILE   *out));

 void file_compress    OF((char  *file, char *mode));

 void file_uncompress  OF((char  *file));

 int  main             OF((int argc, char *argv[]));

 /* ===========================================================================

  * Display error message and exit

  */

 void error(msg)

     const char *msg;

 {

     fprintf(stderr, "%s: %s\n", prog, msg);

     exit(1);

 }

 /* ===========================================================================

  * Compress input to output then close both files.

  */

 void gz_compress(in, out)

     FILE   *in;

     gzFile out;

 {

     local char buf[BUFLEN];

     int len;

     int err;

 #ifdef USE_MMAP

     /* Try first compressing with mmap. If mmap fails (minigzip used in a

      * pipe), use the normal fread loop.

      */

     if (gz_compress_mmap(in, out) == Z_OK) return;

 #endif

     for (;;) {

         len = fread(buf, 1, sizeof(buf), in);

         if (ferror(in)) {

             perror("fread");

             exit(1);

         }

         if (len == 0) break;

         if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));

     }

     fclose(in);

     if (gzclose(out) != Z_OK) error("failed gzclose");

 }

 #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */

 /* Try compressing the input file at once using mmap. Return Z_OK if

  * if success, Z_ERRNO otherwise.

  */

 int gz_compress_mmap(in, out)

     FILE   *in;

     gzFile out;

 {

     int len;

     int err;

     int ifd = fileno(in);

     caddr_t buf;    /* mmap'ed buffer for the entire input file */

     off_t buf_len;  /* length of the input file */

     struct stat sb;

     /* Determine the size of the file, needed for mmap: */

     if (fstat(ifd, &sb) < 0) return Z_ERRNO;

     buf_len = sb.st_size;

     if (buf_len <= 0) return Z_ERRNO;

     /* Now do the actual mmap: */

     buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0); 

     if (buf == (caddr_t)(-1)) return Z_ERRNO;

     /* Compress the whole file at once: */

     len = gzwrite(out, (char *)buf, (unsigned)buf_len);

     if (len != (int)buf_len) error(gzerror(out, &err));

     munmap(buf, buf_len);

     fclose(in);

     if (gzclose(out) != Z_OK) error("failed gzclose");

     return Z_OK;

 }

 #endif /* USE_MMAP */

 /* ===========================================================================

  * Uncompress input to output then close both files.

  */

 void gz_uncompress(in, out)

     gzFile in;

     FILE   *out;

 {

     local char buf[BUFLEN];

     int len;

     int err;

     for (;;) {

         len = gzread(in, buf, sizeof(buf));

         if (len < 0) error (gzerror(in, &err));

         if (len == 0) break;

         if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {

 	    error("failed fwrite");

 	}

     }

     if (fclose(out)) error("failed fclose");

     if (gzclose(in) != Z_OK) error("failed gzclose");

 }

 /* ===========================================================================

  * Compress the given file: create a corresponding .gz file and remove the

  * original.

  */

 void file_compress(file, mode)

     char  *file;

     char  *mode;

 {

     local char outfile[MAX_NAME_LEN];

     FILE  *in;

     gzFile out;

     strcpy(outfile, file);

     strcat(outfile, GZ_SUFFIX);

     in = fopen(file, "rb");

     if (in == NULL) {

         perror(file);

         exit(1);

     }

     out = gzopen(outfile, mode);

     if (out == NULL) {

         fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);

         exit(1);

     }

     gz_compress(in, out);

     unlink(file);

 }

 /* ===========================================================================

  * Uncompress the given file and remove the original.

  */

 void file_uncompress(file)

     char  *file;

 {

     local char buf[MAX_NAME_LEN];

     char *infile, *outfile;

     FILE  *out;

     gzFile in;

     int len = strlen(file);

     strcpy(buf, file);

     if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {

         infile = file;

         outfile = buf;

         outfile[len-3] = '\0';

     } else {

         outfile = file;

         infile = buf;

         strcat(infile, GZ_SUFFIX);

     }

     in = gzopen(infile, "rb");

     if (in == NULL) {

         fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);

         exit(1);

     }

     out = fopen(outfile, "wb");

     if (out == NULL) {

         perror(file);

         exit(1);

     }

     gz_uncompress(in, out);

     unlink(infile);

 }

 /* ===========================================================================

  * Usage:  minigzip [-d] [-f] [-h] [-1 to -9] [files...]

  *   -d : decompress

  *   -f : compress with Z_FILTERED

  *   -h : compress with Z_HUFFMAN_ONLY

  *   -1 to -9 : compression level

  */

 int main(argc, argv)

     int argc;

     char *argv[];

 {

     int uncompr = 0;

     gzFile file;

     char outmode[20];

     strcpy(outmode, "wb6 ");

     prog = argv[0];

     argc--, argv++;

     while (argc > 0) {

       if (strcmp(*argv, "-d") == 0)

 	uncompr = 1;

       else if (strcmp(*argv, "-f") == 0)

 	outmode[3] = 'f';

       else if (strcmp(*argv, "-h") == 0)

 	outmode[3] = 'h';

       else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' &&

 	       (*argv)[2] == 0)

 	outmode[2] = (*argv)[1];

       else

 	break;

       argc--, argv++;

     }

     if (argc == 0) {

         SET_BINARY_MODE(stdin);

         SET_BINARY_MODE(stdout);

         if (uncompr) {

             file = gzdopen(fileno(stdin), "rb");

             if (file == NULL) error("can't gzdopen stdin");

             gz_uncompress(file, stdout);

         } else {

             file = gzdopen(fileno(stdout), outmode);

             if (file == NULL) error("can't gzdopen stdout");

             gz_compress(stdin, file);

         }

     } else {

         do {

             if (uncompr) {

                 file_uncompress(*argv);

             } else {

                 file_compress(*argv, outmode);

             }

         } while (argv++, --argc);

     }

     exit(0);

     return 0; /* to avoid warning */

 }