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Diffstat (limited to 'lib/libz/minigzip.c')
| -rw-r--r-- | lib/libz/minigzip.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/lib/libz/minigzip.c b/lib/libz/minigzip.c new file mode 100644 index 0000000..fcee6a2 --- /dev/null +++ b/lib/libz/minigzip.c @@ -0,0 +1,246 @@ +/* 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 1.10 1996/07/24 13:41:04 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" +#endif +#ifdef RISCOS +# define unlink remove +# define GZ_SUFFIX "-gz" +# define fileno(file) file->__file +#endif + +#ifndef GZ_SUFFIX +# 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 */ +} |
