Implement zlib-based gzip/gunzip/zcat.

2 files changed, 199 insertions, 93 deletions

diff --git a/toys/pending/compress.c b/toys/pending/compress.c
index 1749ee4f..5605a354 100644
--- a/toys/pending/compress.c
+++ b/toys/pending/compress.c
@@ -16,9 +16,6 @@
 // Leave Lrg at end so flag values line up.
 
 USE_COMPRESS(NEWTOY(compress, "zcd9lrg[-cd][!zgLr]", TOYFLAG_USR|TOYFLAG_BIN))
-USE_GZIP(NEWTOY(gzip, USE_GZIP_D("d")"19dcflqStvgLRz[!gLRz]", TOYFLAG_USR|TOYFLAG_BIN))
-USE_ZCAT(NEWTOY(zcat, 0, TOYFLAG_USR|TOYFLAG_BIN))
-USE_GUNZIP(NEWTOY(gunzip, "cflqStv", TOYFLAG_USR|TOYFLAG_BIN))
 
 //zip unzip gzip gunzip zcat
 
@@ -37,40 +34,6 @@ config COMPRESS
     -R	raw
     -z	zip
 
-config GZIP
-  bool "gzip"
-  default y
-  depends on COMPRESS
-  help
-    usage: gzip [-19cfqStvzgLR] [FILE...]
-
-    Compess (deflate) file(s). With no files, compress stdin to stdout.
-
-    On successful decompression, compressed files are replaced with the
-    uncompressed version. The input file is removed and replaced with
-    a new file without the .gz extension (with same ownership/permissions).
-
-    -1	Minimal compression (fastest)
-    -9	Max compression (default)
-    -c	cat to stdout (act as zcat)
-    -f	force (if output file exists, input is tty, unrecognized extension)
-    -q	quiet (no warnings)
-    -S	specify exension (default .*)
-    -t	test compressed file(s)
-    -v	verbose (like -l, but compress files)
-
-    Compression type:
-    -g gzip (default)    -L zlib    -R raw    -z zip
-
-config GZIP_D
-  bool
-  default y
-  depends on GZIP && DECOMPRESS
-  help
-    usage: gzip [-d]
-
-    -d	decompress (act as gunzip)
-
 config DECOMPRESS
   bool "decompress"
   default n
@@ -81,37 +44,6 @@ config DECOMPRESS
 
     -c	compress with -g gzip (default)  -l zlib  -r raw  -z zip
     -d	decompress (autodetects type)
-
-
-config ZCAT
-  bool "zcat"
-  default y
-  depends on DECOMPRESS
-  help
-    usage: zcat [FILE...]
-
-    Decompress deflated file(s) to stdout
-
-config GUNZIP
-  bool "gunzip"
-  default y
-  depends on DECOMPRESS
-  help
-    usage: gunzip [-cflqStv] [FILE...]
-
-    Decompess (deflate) file(s). With no files, compress stdin to stdout.
-
-    On successful decompression, compressed files are replaced with the
-    uncompressed version. The input file is removed and replaced with
-    a new file without the .gz extension (with same ownership/permissions).
-
-    -c	cat to stdout (act as zcat)
-    -f	force (output file exists, input is tty, unrecognized extension)
-    -l	list compressed/uncompressed/ratio/name for each input file.
-    -q	quiet (no warnings)
-    -S	specify exension (default .*)
-    -t	test compressed file(s)
-    -v	verbose (like -l, but decompress files)
 */
 
 #define FOR_compress
@@ -579,28 +511,3 @@ void compress_main(void)
   // todo: this
   printf("hello world");
 }
-
-//#define CLEANUP_compress
-//#define FOR_zcat
-//#include "generated/flags.h"
-
-void zcat_main(void)
-{
-  init_deflate(0);
-
-  loopfiles(toys.optargs, do_zcat);
-}
-
-void gunzip_main(void)
-{
-  init_deflate(0);
-
-  loopfiles(toys.optargs, do_zcat);
-}
-
-void gzip_main(void)
-{
-  init_deflate(1);
-
-  loopfiles(toys.optargs, do_gzip);
-}
diff --git a/toys/pending/gzip.c b/toys/pending/gzip.c
new file mode 100644
index 00000000..f7576c66
--- /dev/null
+++ b/toys/pending/gzip.c
@@ -0,0 +1,199 @@
+/* gzip.c - gzip/gunzip/zcat
+ *
+ * Copyright 2017 The Android Open Source Project
+ *
+ * GZIP RFC: http://www.ietf.org/rfc/rfc1952.txt
+
+// Existing implementations allow all options for all commands.
+USE_GZIP(NEWTOY(gzip,     "cdfk123456789", TOYFLAG_USR|TOYFLAG_BIN))
+USE_GUNZIP(NEWTOY(gunzip, "cdfk123456789", TOYFLAG_USR|TOYFLAG_BIN))
+USE_ZCAT(NEWTOY(zcat,     "cdfk123456789", TOYFLAG_USR|TOYFLAG_BIN))
+
+config GZIP
+  bool "gzip"
+  default y
+  depends on TOYBOX_LIBZ
+  help
+    usage: gzip [-19cdfk] [FILE...]
+
+    Compress files. With no files, compresses stdin to stdout.
+    On success, the input files are removed and replaced by new
+    files with the .gz suffix.
+
+    -c	Output to stdout
+    -d	Decompress (act as gunzip)
+    -f	Force: allow overwrite of output file
+    -k	Keep input files (default is to remove)
+    -#	Compression level 1-9 (1:fastest, 6:default, 9:best)
+
+config GUNZIP
+  bool "gunzip"
+  default y
+  depends on TOYBOX_LIBZ
+  help
+    usage: gunzip [-cfk] [FILE...]
+
+    Decompress files. With no files, decompresses stdin to stdout.
+    On success, the input files are removed and replaced by new
+    files without the .gz suffix.
+
+    -c	Output to stdout (act as zcat)
+    -f	Force: allow read from tty
+    -k	Keep input files (default is to remove)
+
+config ZCAT
+  bool "zcat"
+  default y
+  depends on TOYBOX_LIBZ
+  help
+    usage: zcat [FILE...]
+
+    Decompress files to stdout. Like `gzip -dc`.
+
+    -c	Output to stdout (default)
+    -f	Force: allow read from tty
+*/
+
+#include <zlib.h>
+
+#define FORCE_FLAGS
+#define FOR_gzip
+#include "toys.h"
+
+GLOBALS(
+  int level;
+)
+
+static void fix_time(const char *path, struct stat *sb)
+{
+  struct timespec times[] = { sb->st_atim, sb->st_mtim };
+
+  if (utimensat(AT_FDCWD, path, times, 0)) perror_exit("utimensat");
+}
+
+static void gzerror_exit(gzFile f, char *what)
+{
+  int err;
+  const char *msg = gzerror(f, &err);
+
+  ((err == Z_ERRNO) ? perror_exit : error_exit)("%s: %s", what, msg);
+}
+
+static void do_gunzip(int in_fd, char *arg)
+{
+  struct stat sb;
+  int len, both_files;
+  char *in_name, *out_name;
+  gzFile in;
+  FILE *out;
+
+  // "gunzip x.gz" will decompress "x.gz" to "x".
+  len = strlen(arg);
+  if (len > 3 && !strcmp(arg+len-3, ".gz")) {
+    in_name = strdup(arg);
+    out_name = strdup(arg);
+    out_name[len-3] = '\0';
+  } else if (!strcmp(arg, "-")) {
+    // "-" means stdin; assume output to stdout.
+    // TODO: require -f to read compressed data from tty?
+    in_name = strdup("-");
+    out_name = strdup("-");
+  } else error_exit("unknown suffix: %s", arg);
+
+  if (toys.optflags&FLAG_c) {
+    free(out_name);
+    out_name = strdup("-");
+  }
+
+  both_files = strcmp(in_name, "-") && strcmp(out_name, "-");
+  if (both_files) xstat(in_name, &sb);
+
+  in = gzdopen(in_fd, "r");
+  if (in == NULL) perror_exit("gzdopen");
+  if (!strcmp(out_name, "-")) out = stdout;
+  else {
+    int out_fd = xcreate(out_name,
+      O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL),
+      both_files?sb.st_mode:0666);
+
+    out = xfdopen(out_fd, "w");
+  }
+
+  while ((len = gzread(in, toybuf, sizeof(toybuf))) > 0) {
+    if (fwrite(toybuf, 1, len, out) != (size_t) len) perror_exit("writing");
+  }
+  if (len < 0) gzerror_exit(in, "gzread");
+  if (out != stdout && fclose(out)) perror_exit("writing");
+  if (gzclose(in) != Z_OK) error_exit("gzclose");
+
+  if (both_files) fix_time(out_name, &sb);
+  if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name);
+  free(in_name);
+  free(out_name);
+}
+
+static void do_gzip(int in_fd, char *in_name)
+{
+  size_t len;
+  char *out_name;
+  FILE *in = xfdopen(in_fd, "r");
+  gzFile out;
+  struct stat sb;
+  int both_files, out_fd;
+
+  out_name = (toys.optflags&FLAG_c) ? strdup("-") : xmprintf("%s.gz", in_name);
+  both_files = strcmp(in_name, "-") && strcmp(out_name, "-");
+  if (both_files) xstat(in_name, &sb);
+
+  if (!strcmp(out_name, "-")) out_fd = dup(1);
+  else {
+    out_fd = open(out_name, O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL),
+      both_files?sb.st_mode:0);
+  }
+  if (out_fd == -1) perror_exit("open %s", out_name);
+
+  snprintf(toybuf, sizeof(toybuf), "w%d", TT.level);
+  out = gzdopen(out_fd, toybuf);
+  if (out == NULL) perror_exit("gzdopen %s", out_name);
+
+  while ((len = fread(toybuf, 1, sizeof(toybuf), in)) > 0) {
+    if (gzwrite(out, toybuf, len) != (int) len) gzerror_exit(out, "gzwrite");
+  }
+  if (ferror(in)) perror_exit("fread");
+  if (fclose(in)) perror_exit("fclose");
+  if (gzclose(out) != Z_OK) error_exit("gzclose");
+
+  if (both_files) fix_time(out_name, &sb);
+  if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name);
+  free(out_name);
+}
+
+static void do_gz(int fd, char *name)
+{
+  if (toys.optflags&FLAG_d) do_gunzip(fd, name);
+  else do_gzip(fd, name);
+}
+
+void gzip_main(void)
+{
+  int i = (toys.optflags&0x1ff);
+
+  for (TT.level = (i == 0) ? 6 : 10; i; i >>= 1) --TT.level;
+
+  // With no arguments, go from stdin to stdout.
+  if (!*toys.optargs) toys.optflags |= FLAG_c;
+
+  loopfiles(toys.optargs, do_gz);
+}
+
+void gunzip_main(void)
+{
+  toys.optflags |= FLAG_d;
+  gzip_main();
+}
+
+void zcat_main(void)
+{
+  toys.optflags |= (FLAG_c|FLAG_d);
+  gzip_main();
+}