| /* minigzip.c -- simulate gzip using the zlib compression library |
| * Copyright (C) 1995-2006, 2010, 2011, 2016 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. |
| */ |
| |
| #define _POSIX_SOURCE 1 /* This file needs POSIX for fdopen(). */ |
| #define _POSIX_C_SOURCE 200112 /* For snprintf(). */ |
| |
| #include "zbuild.h" |
| #ifdef ZLIB_COMPAT |
| # include "zlib.h" |
| #else |
| # include "zlib-ng.h" |
| #endif |
| #include <stdio.h> |
| |
| #include <string.h> |
| #include <stdlib.h> |
| |
| #ifdef USE_MMAP |
| # include <sys/types.h> |
| # include <sys/mman.h> |
| # include <sys/stat.h> |
| #endif |
| |
| #ifndef UNALIGNED_OK |
| # include <malloc.h> |
| #endif |
| |
| #if 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 |
| |
| #if defined(_MSC_VER) && _MSC_VER < 1900 |
| # define snprintf _snprintf |
| #endif |
| |
| #if !defined(Z_HAVE_UNISTD_H) && !defined(_LARGEFILE64_SOURCE) |
| #ifndef _WIN32 /* unlink already in stdio.h for Win32 */ |
| extern int unlink (const char *); |
| #endif |
| #endif |
| |
| #ifndef GZ_SUFFIX |
| # define GZ_SUFFIX ".gz" |
| #endif |
| #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1) |
| |
| #ifndef BUFLEN |
| # define BUFLEN 16384 /* read buffer size */ |
| #endif |
| #define BUFLENW (BUFLEN * 3) /* write buffer size */ |
| #define MAX_NAME_LEN 1024 |
| |
| static char *prog; |
| |
| void error (const char *msg); |
| void gz_compress (FILE *in, gzFile out); |
| #ifdef USE_MMAP |
| int gz_compress_mmap (FILE *in, gzFile out); |
| #endif |
| void gz_uncompress (gzFile in, FILE *out); |
| void file_compress (char *file, char *mode, int keep); |
| void file_uncompress (char *file, int keep); |
| int main (int argc, char *argv[]); |
| |
| /* =========================================================================== |
| * Display error message and exit |
| */ |
| void error(const char *msg) { |
| fprintf(stderr, "%s: %s\n", prog, msg); |
| exit(1); |
| } |
| |
| /* =========================================================================== |
| * Compress input to output then close both files. |
| */ |
| |
| void gz_compress(FILE *in, gzFile out) { |
| char *buf = (char *)calloc(BUFLEN, 1); |
| 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, BUFLEN, in); |
| if (ferror(in)) { |
| perror("fread"); |
| exit(1); |
| } |
| if (len == 0) break; |
| |
| if (PREFIX(gzwrite)(out, buf, (unsigned)len) != len) error(PREFIX(gzerror)(out, &err)); |
| } |
| free(buf); |
| fclose(in); |
| if (PREFIX(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(FILE *in, gzFile out) { |
| int len; |
| int err; |
| int ifd = fileno(in); |
| char *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((void *)0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0); |
| if (buf == (char *)(-1)) return Z_ERRNO; |
| |
| /* Compress the whole file at once: */ |
| len = PREFIX(gzwrite)(out, buf, (unsigned)buf_len); |
| |
| if (len != (int)buf_len) error(PREFIX(gzerror)(out, &err)); |
| |
| munmap(buf, buf_len); |
| fclose(in); |
| if (PREFIX(gzclose)(out) != Z_OK) error("failed gzclose"); |
| return Z_OK; |
| } |
| #endif /* USE_MMAP */ |
| |
| /* =========================================================================== |
| * Uncompress input to output then close both files. |
| */ |
| void gz_uncompress(gzFile in, FILE *out) { |
| char *buf = (char *)malloc(BUFLENW); |
| int len; |
| int err; |
| |
| for (;;) { |
| len = PREFIX(gzread)(in, buf, BUFLENW); |
| if (len < 0) error (PREFIX(gzerror)(in, &err)); |
| if (len == 0) break; |
| |
| if ((int)fwrite(buf, 1, (unsigned)len, out) != len) { |
| error("failed fwrite"); |
| } |
| } |
| free(buf); |
| if (fclose(out)) error("failed fclose"); |
| |
| if (PREFIX(gzclose)(in) != Z_OK) error("failed gzclose"); |
| } |
| |
| |
| /* =========================================================================== |
| * Compress the given file: create a corresponding .gz file and remove the |
| * original. |
| */ |
| void file_compress(char *file, char *mode, int keep) { |
| char outfile[MAX_NAME_LEN]; |
| FILE *in; |
| gzFile out; |
| |
| if (strlen(file) + strlen(GZ_SUFFIX) >= sizeof(outfile)) { |
| fprintf(stderr, "%s: filename too long\n", prog); |
| exit(1); |
| } |
| |
| snprintf(outfile, sizeof(outfile), "%s%s", file, GZ_SUFFIX); |
| |
| in = fopen(file, "rb"); |
| if (in == NULL) { |
| perror(file); |
| exit(1); |
| } |
| out = PREFIX(gzopen)(outfile, mode); |
| if (out == NULL) { |
| fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile); |
| exit(1); |
| } |
| gz_compress(in, out); |
| |
| if (!keep) |
| unlink(file); |
| } |
| |
| |
| /* =========================================================================== |
| * Uncompress the given file and remove the original. |
| */ |
| void file_uncompress(char *file, int keep) { |
| char buf[MAX_NAME_LEN]; |
| char *infile, *outfile; |
| FILE *out; |
| gzFile in; |
| size_t len = strlen(file); |
| |
| if (len + strlen(GZ_SUFFIX) >= sizeof(buf)) { |
| fprintf(stderr, "%s: filename too long\n", prog); |
| exit(1); |
| } |
| |
| snprintf(buf, sizeof(buf), "%s", 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; |
| snprintf(buf + len, sizeof(buf) - len, "%s", GZ_SUFFIX); |
| } |
| in = PREFIX(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); |
| |
| if (!keep) |
| unlink(infile); |
| } |
| |
| void show_help(void) { |
| printf("Usage: minigzip [-c] [-d] [-k] [-f|-h|-R|-F|-T] [-A] [-0 to -9] [files...]\n\n" \ |
| " -c : write to standard output\n" \ |
| " -d : decompress\n" \ |
| " -k : keep input files\n" \ |
| " -f : compress with Z_FILTERED\n" \ |
| " -h : compress with Z_HUFFMAN_ONLY\n" \ |
| " -R : compress with Z_RLE\n" \ |
| " -F : compress with Z_FIXED\n" \ |
| " -T : stored raw\n" \ |
| " -A : auto detect type\n" \ |
| " -0 to -9 : compression level\n\n"); |
| } |
| |
| int main(int argc, char *argv[]) { |
| int copyout = 0; |
| int uncompr = 0; |
| int keep = 0; |
| int i = 0; |
| gzFile file; |
| char *bname, outmode[20]; |
| char *strategy = ""; |
| char *level = "6"; |
| char *type = "b"; |
| |
| prog = argv[i]; |
| bname = strrchr(argv[i], '/'); |
| if (bname) |
| bname++; |
| else |
| bname = argv[i]; |
| |
| if (!strcmp(bname, "gunzip")) |
| uncompr = 1; |
| else if (!strcmp(bname, "zcat")) |
| copyout = uncompr = 1; |
| |
| for (i = 1; i < argc; i++) { |
| if (strcmp(argv[i], "-c") == 0) |
| copyout = 1; |
| else if (strcmp(argv[i], "-d") == 0) |
| uncompr = 1; |
| else if (strcmp(argv[i], "-k") == 0) |
| keep = 1; |
| else if (strcmp(argv[i], "-A") == 0) |
| type = ""; |
| else if (argv[i][0] == '-' && (argv[i][1] == 'f' || argv[i][1] == 'h' || |
| argv[i][1] == 'R' || argv[i][1] == 'F' || argv[i][1] == 'T') && argv[i][2] == 0) |
| strategy = argv[i] + 1; |
| else if (argv[i][0] == '-' && argv[i][1] >= '0' && argv[i][1] <= '9' && argv[i][2] == 0) |
| level = argv[i] + 1; |
| else if (strcmp(argv[i], "--help") == 0) { |
| show_help(); |
| return 0; |
| } else if (argv[i][0] == '-') { |
| show_help(); |
| return 64; /* EX_USAGE */ |
| } else { |
| break; |
| } |
| } |
| |
| snprintf(outmode, sizeof(outmode), "w%s%s%s", type, strategy, level); |
| |
| if (i == argc) { |
| SET_BINARY_MODE(stdin); |
| SET_BINARY_MODE(stdout); |
| if (uncompr) { |
| file = PREFIX(gzdopen)(fileno(stdin), "rb"); |
| if (file == NULL) error("can't gzdopen stdin"); |
| gz_uncompress(file, stdout); |
| } else { |
| file = PREFIX(gzdopen)(fileno(stdout), outmode); |
| if (file == NULL) error("can't gzdopen stdout"); |
| gz_compress(stdin, file); |
| } |
| } else { |
| if (copyout) { |
| SET_BINARY_MODE(stdout); |
| } |
| do { |
| if (uncompr) { |
| if (copyout) { |
| file = PREFIX(gzopen)(argv[i], "rb"); |
| if (file == NULL) |
| fprintf(stderr, "%s: can't gzopen %s\n", prog, argv[i]); |
| else |
| gz_uncompress(file, stdout); |
| } else { |
| file_uncompress(argv[i], keep); |
| } |
| } else { |
| if (copyout) { |
| FILE * in = fopen(argv[i], "rb"); |
| |
| if (in == NULL) { |
| perror(argv[i]); |
| } else { |
| file = PREFIX(gzdopen)(fileno(stdout), outmode); |
| if (file == NULL) error("can't gzdopen stdout"); |
| |
| gz_compress(in, file); |
| } |
| |
| } else { |
| file_compress(argv[i], outmode, keep); |
| } |
| } |
| } while (++i < argc); |
| } |
| return 0; |
| } |