LXR toybox/toys/lsb/gzip.c

   1/* gzip.c - gzip/gunzip/zcat
   2 *
   3 * Copyright 2017 The Android Open Source Project
   4 *
   5 * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/gzip.html
   6 * GZIP RFC: http://www.ietf.org/rfc/rfc1952.txt
   7 *
   8 * todo: qtv --rsyncable
   9
  10// gzip.net version allows all options for all commands.
  11USE_GZIP(NEWTOY(gzip,    "ncdfk123456789[-123456789]", TOYFLAG_USR|TOYFLAG_BIN))
  12USE_GUNZIP(NEWTOY(gunzip, "cdfk123456789[-123456789]", TOYFLAG_USR|TOYFLAG_BIN))
  13USE_ZCAT(NEWTOY(zcat,     "cdfk123456789[-123456789]", TOYFLAG_USR|TOYFLAG_BIN))
  14
  15config GZIP
  16  bool "gzip"
  17  default n
  18  help
  19    usage: gzip [-19cdfk] [FILE...]
  20
  21    Compress files. With no files, compresses stdin to stdout.
  22    On success, the input files are removed and replaced by new
  23    files with the .gz suffix.
  24
  25    -c  Output to stdout
  26    -d  Decompress (act as gunzip)
  27    -f  Force: allow overwrite of output file
  28    -k  Keep input files (default is to remove)
  29    -#  Compression level 1-9 (1:fastest, 6:default, 9:best)
  30
  31config GUNZIP
  32  bool "gunzip"
  33  default y
  34  help
  35    usage: gunzip [-cfk] [FILE...]
  36
  37    Decompress files. With no files, decompresses stdin to stdout.
  38    On success, the input files are removed and replaced by new
  39    files without the .gz suffix.
  40
  41    -c  Output to stdout (act as zcat)
  42    -f  Force: allow read from tty
  43    -k  Keep input files (default is to remove)
  44
  45config ZCAT
  46  bool "zcat"
  47  default y
  48  help
  49    usage: zcat [FILE...]
  50
  51    Decompress files to stdout. Like `gzip -dc`.
  52
  53    -f  Force: allow read from tty
  54*/
  55
  56#define FORCE_FLAGS
  57#define FOR_gzip
  58#include "toys.h"
  59
  60GLOBALS(
  61  int level;
  62)
  63
  64// Use assembly optimized zlib code?
  65#if CFG_TOYBOX_LIBZ
  66#include <zlib.h>
  67
  68// Read from in_fd, write to out_fd, decompress if dd else compress
  69static int do_deflate(int in_fd, int out_fd, int dd, int level)
  70{
  71  int len, err = 0;
  72  char *b = "r";
  73  gzFile gz;
  74
  75  if (!dd) {
  76    sprintf(b = toybuf, "w%d", level);
  77    if (out_fd == 1) out_fd = xdup(out_fd);
  78  }
  79  if (!(gz = gzdopen(dd ? in_fd : out_fd, b))) perror_exit("gzdopen");
  80  if (dd) {
  81    if (gzdirect(gz)) error_exit("not gzip");
  82    while ((len = gzread(gz, toybuf, sizeof(toybuf))) > 0)
  83      if (len != writeall(out_fd, toybuf, len)) break;
  84  } else {
  85    while ((len = read(in_fd, toybuf, sizeof(toybuf))) > 0)
  86      if (len != gzwrite(gz, toybuf, len))  break;
  87  }
  88
  89  err = !!len;
  90  if (len>0 || err == Z_ERRNO) perror_msg(dd ? "write" : "read");
  91  if (len<0)
  92    error_msg("%s%s: %s", "gz", dd ? "read" : "write", gzerror(gz, &len));
  93
  94  if (gzclose(gz) != Z_OK) perror_msg("gzclose"), err++;
  95
  96  return err;
  97}
  98
  99// Use toybox's builtin lib/deflate.c
 100#else
 101
 102// Read from in_fd, write to out_fd, decompress if dd else compress
 103static int do_deflate(int in_fd, int out_fd, int dd, int level)
 104{
 105  int x;
 106
 107  if (dd) WOULD_EXIT(x, gunzip_fd(in_fd, out_fd));
 108  else WOULD_EXIT(x, gzip_fd(in_fd, out_fd));
 109
 110  return x;
 111}
 112
 113#endif
 114
 115static void do_gzip(int ifd, char *in)
 116{
 117  struct stat sb;
 118  char *out = 0;
 119  int ofd = 0;
 120
 121  // Are we writing to stdout?
 122  if (!ifd || FLAG(c)) ofd = 1;
 123  if (isatty(ifd)) {
 124    if (!FLAG(f)) return error_msg("%s:need -f to read TTY"+3*!!ifd, in);
 125    else ofd = 1;
 126  }
 127
 128  // Are we reading file.gz to write to file?
 129  if (!ofd) {
 130    if (fstat(ifd, &sb)) return perror_msg("%s", in);
 131
 132    // Add or remove .gz suffix as necessary
 133    if (!FLAG(d)) out = xmprintf("%s%s", in, ".gz");
 134    else if ((out = strend(in, ".gz"))>in) out = xstrndup(in, out-in);
 135    else return error_msg("no .gz: %s", in);
 136
 137    ofd = xcreate(out, O_CREAT|O_WRONLY|WARN_ONLY|(O_EXCL*!FLAG(f)),sb.st_mode);
 138    if (ofd == -1) return;
 139  }
 140
 141  if (do_deflate(ifd, ofd, FLAG(d), TT.level)) in = out;
 142
 143  if (out) {
 144    struct timespec times[] = {sb.st_atim, sb.st_mtim};
 145
 146    if (utimensat(AT_FDCWD, out, times, 0)) perror_exit("utimensat");
 147    if (chmod(out, sb.st_mode)) perror_exit("chmod");
 148    close(ofd);
 149    if (!FLAG(k) && in && unlink(in)) perror_msg("unlink %s", in);
 150    free(out);
 151  }
 152}
 153
 154void gzip_main(void)
 155{
 156  // This depends on 1-9 being at the end of the option list
 157  for (TT.level = 0; TT.level<9; TT.level++)
 158    if ((toys.optflags>>TT.level)&1) break;
 159  if (!(TT.level = 9-TT.level)) TT.level = 6;
 160
 161  loopfiles(toys.optargs, do_gzip);
 162}
 163
 164void gunzip_main(void)
 165{
 166  toys.optflags |= FLAG_d;
 167  gzip_main();
 168}
 169
 170void zcat_main(void)
 171{
 172  toys.optflags |= (FLAG_c|FLAG_d);
 173  gzip_main();
 174}
 175