| /* minigzip.c -- simulate gzip using the zlib compression library |
| * Copyright (C) 1995-1996 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: minigzip.c,v 1.9 1996/05/22 11:52:32 me Exp $ */ |
| |
| #include <stdio.h> |
| #include "zlib.h" |
| |
| #ifdef STDC |
| # include <string.h> |
| # include <stdlib.h> |
| #else |
| extern void exit OF((int)); |
| #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" |
| #else |
| # define GZ_SUFFIX ".gz" |
| #endif |
| #define SUFFIX_LEN sizeof(GZ_SUFFIX) |
| |
| extern int unlink OF((const char *)); |
| |
| #define BUFLEN 4096 |
| #define MAX_NAME_LEN 1024 |
| |
| #define local static |
| /* For MSDOS and other systems with limitation on stack size. For Unix, |
| #define local |
| works also. |
| */ |
| |
| char *prog; |
| |
| void error OF((const char *msg)); |
| void gz_compress OF((FILE *in, gzFile out)); |
| void gz_uncompress OF((gzFile in, FILE *out)); |
| void file_compress OF((char *file)); |
| 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; |
| |
| 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"); |
| } |
| |
| /* =========================================================================== |
| * 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) |
| char *file; |
| { |
| 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, "wb"); /* use "wb9" for maximal compression */ |
| 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] [files...] |
| */ |
| |
| int main(argc, argv) |
| int argc; |
| char *argv[]; |
| { |
| int uncompr = 0; |
| gzFile file; |
| |
| prog = argv[0]; |
| argc--, argv++; |
| |
| if (argc > 0) { |
| uncompr = (strcmp(*argv, "-d") == 0); |
| if (uncompr) { |
| 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), "wb"); /* "wb9" for max compr. */ |
| if (file == NULL) error("can't gzdopen stdout"); |
| gz_compress(stdin, file); |
| } |
| } else { |
| do { |
| if (uncompr) { |
| file_uncompress(*argv); |
| } else { |
| file_compress(*argv); |
| } |
| } while (argv++, --argc); |
| } |
| exit(0); |
| return 0; /* to avoid warning */ |
| } |