1 /* gzip.c - gzip/gunzip/zcat
2 *
3 * Copyright 2017 The Android Open Source Project
4 *
5 * GZIP RFC: http://www.ietf.org/rfc/rfc1952.txt
6
7 // Existing implementations allow all options for all commands.
8 USE_GZIP(NEWTOY(gzip, "cdfk123456789", TOYFLAG_USR|TOYFLAG_BIN))
9 USE_GUNZIP(NEWTOY(gunzip, "cdfk123456789", TOYFLAG_USR|TOYFLAG_BIN))
10 USE_ZCAT(NEWTOY(zcat, "cdfk123456789", TOYFLAG_USR|TOYFLAG_BIN))
11
12 config GZIP
13 bool "gzip"
14 default y
15 depends on TOYBOX_LIBZ
16 help
17 usage: gzip [-19cdfk] [FILE...]
18
19 Compress files. With no files, compresses stdin to stdout.
20 On success, the input files are removed and replaced by new
21 files with the .gz suffix.
22
23 -c Output to stdout
24 -d Decompress (act as gunzip)
25 -f Force: allow overwrite of output file
26 -k Keep input files (default is to remove)
27 -# Compression level 1-9 (1:fastest, 6:default, 9:best)
28
29 config GUNZIP
30 bool "gunzip"
31 default y
32 depends on TOYBOX_LIBZ
33 help
34 usage: gunzip [-cfk] [FILE...]
35
36 Decompress files. With no files, decompresses stdin to stdout.
37 On success, the input files are removed and replaced by new
38 files without the .gz suffix.
39
40 -c Output to stdout (act as zcat)
41 -f Force: allow read from tty
42 -k Keep input files (default is to remove)
43
44 config ZCAT
45 bool "zcat"
46 default y
47 depends on TOYBOX_LIBZ
48 help
49 usage: zcat [FILE...]
50
51 Decompress files to stdout. Like `gzip -dc`.
52
53 -c Output to stdout (default)
54 -f Force: allow read from tty
55 */
56
57 #include <zlib.h>
58
59 #define FORCE_FLAGS
60 #define FOR_gzip
61 #include "toys.h"
62
GLOBALS(int level;)63 GLOBALS(
64 int level;
65 )
66
67 static void fix_time(const char *path, struct stat *sb)
68 {
69 struct timespec times[] = { sb->st_atim, sb->st_mtim };
70
71 if (utimensat(AT_FDCWD, path, times, 0)) perror_exit("utimensat");
72 }
73
gzerror_exit(gzFile f,char * what)74 static void gzerror_exit(gzFile f, char *what)
75 {
76 int err;
77 const char *msg = gzerror(f, &err);
78
79 ((err == Z_ERRNO) ? perror_exit : error_exit)("%s: %s", what, msg);
80 }
81
do_gunzip(int in_fd,char * arg)82 static void do_gunzip(int in_fd, char *arg)
83 {
84 struct stat sb;
85 int len, both_files;
86 char *in_name, *out_name;
87 gzFile in;
88 FILE *out;
89
90 // "gunzip x.gz" will decompress "x.gz" to "x".
91 len = strlen(arg);
92 if (len > 3 && !strcmp(arg+len-3, ".gz")) {
93 in_name = strdup(arg);
94 out_name = strdup(arg);
95 out_name[len-3] = '\0';
96 } else if (!strcmp(arg, "-")) {
97 // "-" means stdin; assume output to stdout.
98 // TODO: require -f to read compressed data from tty?
99 in_name = strdup("-");
100 out_name = strdup("-");
101 } else error_exit("unknown suffix: %s", arg);
102
103 if (toys.optflags&FLAG_c) {
104 free(out_name);
105 out_name = strdup("-");
106 }
107
108 both_files = strcmp(in_name, "-") && strcmp(out_name, "-");
109 if (both_files) xstat(in_name, &sb);
110
111 in = gzdopen(in_fd, "r");
112 if (in == NULL) perror_exit("gzdopen");
113 if (!strcmp(out_name, "-")) out = stdout;
114 else {
115 int out_fd = xcreate(out_name,
116 O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL),
117 both_files?sb.st_mode:0666);
118
119 out = xfdopen(out_fd, "w");
120 }
121
122 while ((len = gzread(in, toybuf, sizeof(toybuf))) > 0) {
123 if (fwrite(toybuf, 1, len, out) != (size_t) len) perror_exit("writing");
124 }
125 if (len < 0) gzerror_exit(in, "gzread");
126 if (out != stdout && fclose(out)) perror_exit("writing");
127 if (gzclose(in) != Z_OK) error_exit("gzclose");
128
129 if (both_files) fix_time(out_name, &sb);
130 if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name);
131 free(in_name);
132 free(out_name);
133 }
134
do_gzip(int in_fd,char * in_name)135 static void do_gzip(int in_fd, char *in_name)
136 {
137 size_t len;
138 char *out_name;
139 FILE *in = xfdopen(in_fd, "r");
140 gzFile out;
141 struct stat sb;
142 int both_files, out_fd;
143
144 out_name = (toys.optflags&FLAG_c) ? strdup("-") : xmprintf("%s.gz", in_name);
145 both_files = strcmp(in_name, "-") && strcmp(out_name, "-");
146 if (both_files) xstat(in_name, &sb);
147
148 if (!strcmp(out_name, "-")) out_fd = dup(1);
149 else {
150 out_fd = open(out_name, O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL),
151 both_files?sb.st_mode:0);
152 }
153 if (out_fd == -1) perror_exit("open %s", out_name);
154
155 snprintf(toybuf, sizeof(toybuf), "w%d", TT.level);
156 out = gzdopen(out_fd, toybuf);
157 if (out == NULL) perror_exit("gzdopen %s", out_name);
158
159 while ((len = fread(toybuf, 1, sizeof(toybuf), in)) > 0) {
160 if (gzwrite(out, toybuf, len) != (int) len) gzerror_exit(out, "gzwrite");
161 }
162 if (ferror(in)) perror_exit("fread");
163 if (fclose(in)) perror_exit("fclose");
164 if (gzclose(out) != Z_OK) error_exit("gzclose");
165
166 if (both_files) fix_time(out_name, &sb);
167 if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name);
168 free(out_name);
169 }
170
do_gz(int fd,char * name)171 static void do_gz(int fd, char *name)
172 {
173 if (toys.optflags&FLAG_d) do_gunzip(fd, name);
174 else do_gzip(fd, name);
175 }
176
gzip_main(void)177 void gzip_main(void)
178 {
179 int i = (toys.optflags&0x1ff);
180
181 for (TT.level = (i == 0) ? 6 : 10; i; i >>= 1) --TT.level;
182
183 // With no arguments, go from stdin to stdout.
184 if (!*toys.optargs) toys.optflags |= FLAG_c;
185
186 loopfiles(toys.optargs, do_gz);
187 }
188
gunzip_main(void)189 void gunzip_main(void)
190 {
191 toys.optflags |= FLAG_d;
192 gzip_main();
193 }
194
zcat_main(void)195 void zcat_main(void)
196 {
197 toys.optflags |= (FLAG_c|FLAG_d);
198 gzip_main();
199 }
200