/* minigzip.c -- simulate gzip using the zlib compression library * Copyright (C) 1995-2002 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) || defined(__CYGWIN__)#  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#endifchar *prog;void error            OF((const char *msg));void gz_compress      OF((FILE   *in, gzFile out));#ifdef USE_MMAPint  gz_compress_mmap OF((FILE   *in, gzFile out));#endifvoid 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 = (int)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;    uInt len = (uInt)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] [-r] [-1 to -9] [files...] *   -d : decompress *   -f : compress with Z_FILTERED *   -h : compress with Z_HUFFMAN_ONLY *   -r : compress with Z_RLE *   -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 (strcmp(*argv, "-r") == 0)        outmode[3] = 'R';      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);    }    return 0;}