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author | Elliott Hughes | 2017-04-10 12:56:40 -0500 |
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committer | Elliott Hughes | 2017-04-10 12:56:40 -0500 |
commit | 455567f78c514b0547466edf635b57116b89f71b (patch) | |
tree | 531b154030da00863e61cde5447b60127f6c95f8 /toolbox/gzip.c | |
parent | ebc87c98e35327e7403ed767c935a8e6a02b6f03 (diff) | |
download | platform-system-core-455567f78c514b0547466edf635b57116b89f71b.tar.gz platform-system-core-455567f78c514b0547466edf635b57116b89f71b.tar.xz platform-system-core-455567f78c514b0547466edf635b57116b89f71b.zip |
Add a reasonably full implementation of gzip/gunzip/zcat.
Bug: http://b/36653902
Test: ran tests
Change-Id: Ibda577ba1d2aea5c4796eb632edd4c6d5e50592e
Diffstat (limited to 'toolbox/gzip.c')
-rw-r--r-- | toolbox/gzip.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/toolbox/gzip.c b/toolbox/gzip.c new file mode 100644 index 000000000..62c451830 --- /dev/null +++ b/toolbox/gzip.c | |||
@@ -0,0 +1,261 @@ | |||
1 | /* gzip.c - gzip/gunzip/zcat tools for gzip data | ||
2 | * | ||
3 | * Copyright 2017 The Android Open Source Project | ||
4 | * | ||
5 | * GZIP RFC: http://www.ietf.org/rfc/rfc1952.txt | ||
6 | |||
7 | TODO: port to toybox. | ||
8 | |||
9 | */ | ||
10 | |||
11 | #define _GNU_SOURCE | ||
12 | |||
13 | #include <errno.h> | ||
14 | #include <error.h> | ||
15 | #include <fcntl.h> | ||
16 | #include <getopt.h> | ||
17 | #include <stdio.h> | ||
18 | #include <stdlib.h> | ||
19 | #include <string.h> | ||
20 | #include <sys/stat.h> | ||
21 | |||
22 | #include <zlib.h> | ||
23 | |||
24 | // toybox-style flags/globals. | ||
25 | #define FLAG_c 1 | ||
26 | #define FLAG_d 2 | ||
27 | #define FLAG_f 4 | ||
28 | #define FLAG_k 8 | ||
29 | static struct { | ||
30 | int optflags; | ||
31 | } toys; | ||
32 | static struct { | ||
33 | int level; | ||
34 | } TT; | ||
35 | |||
36 | static void xstat(const char *path, struct stat *sb) | ||
37 | { | ||
38 | if (stat(path, sb)) error(1, errno, "stat %s", path); | ||
39 | } | ||
40 | |||
41 | static void fix_time(const char *path, struct stat *sb) | ||
42 | { | ||
43 | struct timespec times[] = { sb->st_atim, sb->st_mtim }; | ||
44 | |||
45 | if (utimensat(AT_FDCWD, path, times, 0)) error(1, errno, "utimes"); | ||
46 | } | ||
47 | |||
48 | static FILE *xfdopen(const char *name, int flags, mode_t open_mode, | ||
49 | const char *mode) | ||
50 | { | ||
51 | FILE *fp; | ||
52 | int fd; | ||
53 | |||
54 | if (!strcmp(name, "-")) fd = dup((*mode == 'r') ? 0 : 1); | ||
55 | else fd = open(name, flags, open_mode); | ||
56 | |||
57 | if (fd == -1) error(1, errno, "open %s (%s)", name, mode); | ||
58 | fp = fdopen(fd, mode); | ||
59 | if (fp == NULL) error(1, errno, "fopen %s (%s)", name, mode); | ||
60 | return fp; | ||
61 | } | ||
62 | |||
63 | static gzFile xgzopen(const char *name, int flags, mode_t open_mode, | ||
64 | const char *mode) | ||
65 | { | ||
66 | gzFile f; | ||
67 | int fd; | ||
68 | |||
69 | if (!strcmp(name, "-")) fd = dup((*mode == 'r') ? 0 : 1); | ||
70 | else fd = open(name, flags, open_mode); | ||
71 | |||
72 | if (fd == -1) error(1, errno, "open %s (%s)", name, mode); | ||
73 | f = gzdopen(fd, mode); | ||
74 | if (f == NULL) error(1, errno, "gzdopen %s (%s)", name, mode); | ||
75 | return f; | ||
76 | } | ||
77 | |||
78 | static void gzfatal(gzFile f, char *what) | ||
79 | { | ||
80 | int err; | ||
81 | const char *msg = gzerror(f, &err); | ||
82 | |||
83 | error(1, (err == Z_ERRNO) ? errno : 0, "%s: %s", what, msg); | ||
84 | } | ||
85 | |||
86 | static void gunzip(char *arg) | ||
87 | { | ||
88 | struct stat sb; | ||
89 | char buf[BUFSIZ]; | ||
90 | int len, both_files; | ||
91 | char *in_name, *out_name; | ||
92 | gzFile in; | ||
93 | FILE *out; | ||
94 | |||
95 | // "gunzip x.gz" will decompress "x.gz" to "x". | ||
96 | len = strlen(arg); | ||
97 | if (len > 3 && !strcmp(arg+len-3, ".gz")) { | ||
98 | in_name = strdup(arg); | ||
99 | out_name = strdup(arg); | ||
100 | out_name[len-3] = '\0'; | ||
101 | } else if (!strcmp(arg, "-")) { | ||
102 | // "-" means stdin; assume output to stdout. | ||
103 | // TODO: require -f to read compressed data from tty? | ||
104 | in_name = strdup("-"); | ||
105 | out_name = strdup("-"); | ||
106 | } else error(1, 0, "unknown suffix"); | ||
107 | |||
108 | if (toys.optflags&FLAG_c) { | ||
109 | free(out_name); | ||
110 | out_name = strdup("-"); | ||
111 | } | ||
112 | |||
113 | both_files = strcmp(in_name, "-") && strcmp(out_name, "-"); | ||
114 | if (both_files) xstat(in_name, &sb); | ||
115 | |||
116 | in = xgzopen(in_name, O_RDONLY, 0, "r"); | ||
117 | out = xfdopen(out_name, O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL), | ||
118 | both_files?sb.st_mode:0666, "w"); | ||
119 | |||
120 | while ((len = gzread(in, buf, sizeof(buf))) > 0) { | ||
121 | if (fwrite(buf, 1, len, out) != (size_t) len) error(1, errno, "fwrite"); | ||
122 | } | ||
123 | if (len < 0) gzfatal(in, "gzread"); | ||
124 | if (fclose(out)) error(1, errno, "fclose"); | ||
125 | if (gzclose(in) != Z_OK) error(1, 0, "gzclose"); | ||
126 | |||
127 | if (both_files) fix_time(out_name, &sb); | ||
128 | if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name); | ||
129 | free(in_name); | ||
130 | free(out_name); | ||
131 | } | ||
132 | |||
133 | static void gzip(char *in_name) | ||
134 | { | ||
135 | char buf[BUFSIZ]; | ||
136 | size_t len; | ||
137 | char *out_name; | ||
138 | FILE *in; | ||
139 | gzFile out; | ||
140 | struct stat sb; | ||
141 | int both_files; | ||
142 | |||
143 | if (toys.optflags&FLAG_c) { | ||
144 | out_name = strdup("-"); | ||
145 | } else { | ||
146 | if (asprintf(&out_name, "%s.gz", in_name) == -1) { | ||
147 | error(1, errno, "asprintf"); | ||
148 | } | ||
149 | } | ||
150 | |||
151 | both_files = strcmp(in_name, "-") && strcmp(out_name, "-"); | ||
152 | if (both_files) xstat(in_name, &sb); | ||
153 | |||
154 | snprintf(buf, sizeof(buf), "w%d", TT.level); | ||
155 | in = xfdopen(in_name, O_RDONLY, 0, "r"); | ||
156 | out = xgzopen(out_name, O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL), | ||
157 | both_files?sb.st_mode:0, buf); | ||
158 | |||
159 | while ((len = fread(buf, 1, sizeof(buf), in)) > 0) { | ||
160 | if (gzwrite(out, buf, len) != (int) len) gzfatal(out, "gzwrite"); | ||
161 | } | ||
162 | if (ferror(in)) error(1, errno, "fread"); | ||
163 | if (fclose(in)) error(1, errno, "fclose"); | ||
164 | if (gzclose(out) != Z_OK) error(1, 0, "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 | |||
171 | static void do_file(char *arg) | ||
172 | { | ||
173 | if (toys.optflags&FLAG_d) gunzip(arg); | ||
174 | else gzip(arg); | ||
175 | } | ||
176 | |||
177 | static void usage() | ||
178 | { | ||
179 | char *cmd = basename(getprogname()); | ||
180 | |||
181 | printf("usage: %s [-c] [-d] [-f] [-#] [FILE...]\n", cmd); | ||
182 | printf("\n"); | ||
183 | if (!strcmp(cmd, "zcat")) { | ||
184 | printf("Decompress files to stdout. Like `gzip -dc`.\n"); | ||
185 | printf("\n"); | ||
186 | printf("-c\tOutput to stdout\n"); | ||
187 | printf("-f\tForce: allow read from tty\n"); | ||
188 | } else if (!strcmp(cmd, "gunzip")) { | ||
189 | printf("Decompress files. With no files, decompresses stdin to stdout.\n"); | ||
190 | printf("On success, the input files are removed and replaced by new\n"); | ||
191 | printf("files without the .gz suffix.\n"); | ||
192 | printf("\n"); | ||
193 | printf("-c\tOutput to stdout\n"); | ||
194 | printf("-f\tForce: allow read from tty\n"); | ||
195 | printf("-k\tKeep input files (don't remove)\n"); | ||
196 | } else { // gzip | ||
197 | printf("Compress files. With no files, compresses stdin to stdout.\n"); | ||
198 | printf("On success, the input files are removed and replaced by new\n"); | ||
199 | printf("files with the .gz suffix.\n"); | ||
200 | printf("\n"); | ||
201 | printf("-c\tOutput to stdout\n"); | ||
202 | printf("-d\tDecompress (act as gunzip)\n"); | ||
203 | printf("-f\tForce: allow overwrite of output file\n"); | ||
204 | printf("-k\tKeep input files (don't remove)\n"); | ||
205 | printf("-#\tCompression level 1-9 (1:fastest, 6:default, 9:best)\n"); | ||
206 | } | ||
207 | printf("\n"); | ||
208 | } | ||
209 | |||
210 | int main(int argc, char *argv[]) | ||
211 | { | ||
212 | char *cmd = basename(argv[0]); | ||
213 | int opt_ch; | ||
214 | |||
215 | toys.optflags = 0; | ||
216 | TT.level = 6; | ||
217 | |||
218 | if (!strcmp(cmd, "gunzip")) { | ||
219 | // gunzip == gzip -d | ||
220 | toys.optflags = FLAG_d; | ||
221 | } else if (!strcmp(cmd, "zcat")) { | ||
222 | // zcat == gzip -dc | ||
223 | toys.optflags = (FLAG_c|FLAG_d); | ||
224 | } | ||
225 | |||
226 | while ((opt_ch = getopt(argc, argv, "cdfhk123456789")) != -1) { | ||
227 | switch (opt_ch) { | ||
228 | case 'c': toys.optflags |= FLAG_c; break; | ||
229 | case 'd': toys.optflags |= FLAG_d; break; | ||
230 | case 'f': toys.optflags |= FLAG_f; break; | ||
231 | case 'k': toys.optflags |= FLAG_k; break; | ||
232 | |||
233 | case '1': | ||
234 | case '2': | ||
235 | case '3': | ||
236 | case '4': | ||
237 | case '5': | ||
238 | case '6': | ||
239 | case '7': | ||
240 | case '8': | ||
241 | case '9': | ||
242 | TT.level = opt_ch - '0'; | ||
243 | break; | ||
244 | |||
245 | default: | ||
246 | usage(); | ||
247 | return 1; | ||
248 | } | ||
249 | } | ||
250 | |||
251 | if (optind == argc) { | ||
252 | // With no arguments, we go from stdin to stdout. | ||
253 | toys.optflags |= FLAG_c; | ||
254 | do_file("-"); | ||
255 | return 0; | ||
256 | } | ||
257 | |||
258 | // Otherwise process each file in turn. | ||
259 | while (optind < argc) do_file(argv[optind++]); | ||
260 | return 0; | ||
261 | } | ||