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ba67aaf2 ÆAB |
1 | /* |
2 | * sh-i18n--envsubst.c - a stripped-down version of gettext's envsubst(1) | |
3 | * | |
4 | * Copyright (C) 2010 Ævar Arnfjörð Bjarmason | |
5 | * | |
6 | * This is a modified version of | |
7 | * 67d0871a8c:gettext-runtime/src/envsubst.c from the gettext.git | |
8 | * repository. It has been stripped down to only implement the | |
9 | * envsubst(1) features that we need in the git-sh-i18n fallbacks. | |
10 | * | |
11 | * The "Close standard error" part in main() is from | |
12 | * 8dac033df0:gnulib-local/lib/closeout.c. The copyright notices for | |
13 | * both files are reproduced immediately below. | |
14 | */ | |
15 | ||
16 | #include "git-compat-util.h" | |
17 | ||
18 | /* Substitution of environment variables in shell format strings. | |
19 | Copyright (C) 2003-2007 Free Software Foundation, Inc. | |
20 | Written by Bruno Haible <bruno@clisp.org>, 2003. | |
21 | ||
22 | This program is free software; you can redistribute it and/or modify | |
23 | it under the terms of the GNU General Public License as published by | |
24 | the Free Software Foundation; either version 2, or (at your option) | |
25 | any later version. | |
26 | ||
27 | This program is distributed in the hope that it will be useful, | |
28 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
29 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
30 | GNU General Public License for more details. | |
31 | ||
32 | You should have received a copy of the GNU General Public License | |
33 | along with this program; if not, write to the Free Software Foundation, | |
34 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
35 | ||
36 | /* closeout.c - close standard output and standard error | |
37 | Copyright (C) 1998-2007 Free Software Foundation, Inc. | |
38 | ||
39 | This program is free software; you can redistribute it and/or modify | |
40 | it under the terms of the GNU General Public License as published by | |
41 | the Free Software Foundation; either version 2, or (at your option) | |
42 | any later version. | |
43 | ||
44 | This program is distributed in the hope that it will be useful, | |
45 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
46 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
47 | GNU General Public License for more details. | |
48 | ||
49 | You should have received a copy of the GNU General Public License | |
50 | along with this program; if not, write to the Free Software Foundation, | |
51 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
52 | ||
53 | #include <errno.h> | |
ba67aaf2 ÆAB |
54 | #include <stdio.h> |
55 | #include <stdlib.h> | |
56 | #include <string.h> | |
57 | ||
58 | /* If true, substitution shall be performed on all variables. */ | |
59 | static unsigned short int all_variables; | |
60 | ||
61 | /* Forward declaration of local functions. */ | |
62 | static void print_variables (const char *string); | |
63 | static void note_variables (const char *string); | |
64 | static void subst_from_stdin (void); | |
65 | ||
66 | int | |
67 | main (int argc, char *argv[]) | |
68 | { | |
69 | /* Default values for command line options. */ | |
600a6a68 | 70 | /* unsigned short int show_variables = 0; */ |
ba67aaf2 ÆAB |
71 | |
72 | switch (argc) | |
73 | { | |
74 | case 1: | |
75 | error ("we won't substitute all variables on stdin for you"); | |
8c92516f | 76 | break; |
ba67aaf2 ÆAB |
77 | /* |
78 | all_variables = 1; | |
79 | subst_from_stdin (); | |
80 | */ | |
81 | case 2: | |
82 | /* echo '$foo and $bar' | git sh-i18n--envsubst --variables '$foo and $bar' */ | |
83 | all_variables = 0; | |
84 | note_variables (argv[1]); | |
85 | subst_from_stdin (); | |
86 | break; | |
87 | case 3: | |
88 | /* git sh-i18n--envsubst --variables '$foo and $bar' */ | |
89 | if (strcmp(argv[1], "--variables")) | |
90 | error ("first argument must be --variables when two are given"); | |
600a6a68 | 91 | /* show_variables = 1; */ |
ba67aaf2 ÆAB |
92 | print_variables (argv[2]); |
93 | break; | |
94 | default: | |
95 | error ("too many arguments"); | |
96 | break; | |
97 | } | |
98 | ||
99 | /* Close standard error. This is simpler than fwriteerror_no_ebadf, because | |
100 | upon failure we don't need an errno - all we can do at this point is to | |
101 | set an exit status. */ | |
102 | errno = 0; | |
103 | if (ferror (stderr) || fflush (stderr)) | |
104 | { | |
105 | fclose (stderr); | |
106 | exit (EXIT_FAILURE); | |
107 | } | |
108 | if (fclose (stderr) && errno != EBADF) | |
109 | exit (EXIT_FAILURE); | |
110 | ||
111 | exit (EXIT_SUCCESS); | |
112 | } | |
113 | ||
114 | /* Parse the string and invoke the callback each time a $VARIABLE or | |
115 | ${VARIABLE} construct is seen, where VARIABLE is a nonempty sequence | |
116 | of ASCII alphanumeric/underscore characters, starting with an ASCII | |
117 | alphabetic/underscore character. | |
118 | We allow only ASCII characters, to avoid dependencies w.r.t. the current | |
119 | encoding: While "${\xe0}" looks like a variable access in ISO-8859-1 | |
120 | encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030, | |
121 | SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these | |
122 | encodings. */ | |
123 | static void | |
124 | find_variables (const char *string, | |
125 | void (*callback) (const char *var_ptr, size_t var_len)) | |
126 | { | |
127 | for (; *string != '\0';) | |
128 | if (*string++ == '$') | |
129 | { | |
130 | const char *variable_start; | |
131 | const char *variable_end; | |
132 | unsigned short int valid; | |
133 | char c; | |
134 | ||
135 | if (*string == '{') | |
136 | string++; | |
137 | ||
138 | variable_start = string; | |
139 | c = *string; | |
140 | if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') | |
141 | { | |
142 | do | |
143 | c = *++string; | |
144 | while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') | |
145 | || (c >= '0' && c <= '9') || c == '_'); | |
146 | variable_end = string; | |
147 | ||
148 | if (variable_start[-1] == '{') | |
149 | { | |
150 | if (*string == '}') | |
151 | { | |
152 | string++; | |
153 | valid = 1; | |
154 | } | |
155 | else | |
156 | valid = 0; | |
157 | } | |
158 | else | |
159 | valid = 1; | |
160 | ||
161 | if (valid) | |
162 | callback (variable_start, variable_end - variable_start); | |
163 | } | |
164 | } | |
165 | } | |
166 | ||
167 | ||
168 | /* Print a variable to stdout, followed by a newline. */ | |
169 | static void | |
170 | print_variable (const char *var_ptr, size_t var_len) | |
171 | { | |
172 | fwrite (var_ptr, var_len, 1, stdout); | |
173 | putchar ('\n'); | |
174 | } | |
175 | ||
176 | /* Print the variables contained in STRING to stdout, each one followed by a | |
177 | newline. */ | |
178 | static void | |
179 | print_variables (const char *string) | |
180 | { | |
181 | find_variables (string, &print_variable); | |
182 | } | |
183 | ||
184 | ||
185 | /* Type describing list of immutable strings, | |
186 | implemented using a dynamic array. */ | |
187 | typedef struct string_list_ty string_list_ty; | |
188 | struct string_list_ty | |
189 | { | |
190 | const char **item; | |
191 | size_t nitems; | |
192 | size_t nitems_max; | |
193 | }; | |
194 | ||
195 | /* Initialize an empty list of strings. */ | |
196 | static inline void | |
197 | string_list_init (string_list_ty *slp) | |
198 | { | |
199 | slp->item = NULL; | |
200 | slp->nitems = 0; | |
201 | slp->nitems_max = 0; | |
202 | } | |
203 | ||
204 | /* Append a single string to the end of a list of strings. */ | |
205 | static inline void | |
206 | string_list_append (string_list_ty *slp, const char *s) | |
207 | { | |
208 | /* Grow the list. */ | |
209 | if (slp->nitems >= slp->nitems_max) | |
210 | { | |
211 | size_t nbytes; | |
212 | ||
213 | slp->nitems_max = slp->nitems_max * 2 + 4; | |
214 | nbytes = slp->nitems_max * sizeof (slp->item[0]); | |
215 | slp->item = (const char **) xrealloc (slp->item, nbytes); | |
216 | } | |
217 | ||
218 | /* Add the string to the end of the list. */ | |
219 | slp->item[slp->nitems++] = s; | |
220 | } | |
221 | ||
222 | /* Compare two strings given by reference. */ | |
223 | static int | |
224 | cmp_string (const void *pstr1, const void *pstr2) | |
225 | { | |
226 | const char *str1 = *(const char **)pstr1; | |
227 | const char *str2 = *(const char **)pstr2; | |
228 | ||
229 | return strcmp (str1, str2); | |
230 | } | |
231 | ||
232 | /* Sort a list of strings. */ | |
233 | static inline void | |
234 | string_list_sort (string_list_ty *slp) | |
235 | { | |
236 | if (slp->nitems > 0) | |
237 | qsort (slp->item, slp->nitems, sizeof (slp->item[0]), cmp_string); | |
238 | } | |
239 | ||
240 | /* Test whether a string list contains a given string. */ | |
241 | static inline int | |
242 | string_list_member (const string_list_ty *slp, const char *s) | |
243 | { | |
244 | size_t j; | |
245 | ||
246 | for (j = 0; j < slp->nitems; ++j) | |
247 | if (strcmp (slp->item[j], s) == 0) | |
248 | return 1; | |
249 | return 0; | |
250 | } | |
251 | ||
252 | /* Test whether a sorted string list contains a given string. */ | |
253 | static int | |
254 | sorted_string_list_member (const string_list_ty *slp, const char *s) | |
255 | { | |
256 | size_t j1, j2; | |
257 | ||
258 | j1 = 0; | |
259 | j2 = slp->nitems; | |
260 | if (j2 > 0) | |
261 | { | |
262 | /* Binary search. */ | |
263 | while (j2 - j1 > 1) | |
264 | { | |
265 | /* Here we know that if s is in the list, it is at an index j | |
266 | with j1 <= j < j2. */ | |
267 | size_t j = (j1 + j2) >> 1; | |
268 | int result = strcmp (slp->item[j], s); | |
269 | ||
270 | if (result > 0) | |
271 | j2 = j; | |
272 | else if (result == 0) | |
273 | return 1; | |
274 | else | |
275 | j1 = j + 1; | |
276 | } | |
277 | if (j2 > j1) | |
278 | if (strcmp (slp->item[j1], s) == 0) | |
279 | return 1; | |
280 | } | |
281 | return 0; | |
282 | } | |
283 | ||
284 | ||
285 | /* Set of variables on which to perform substitution. | |
286 | Used only if !all_variables. */ | |
287 | static string_list_ty variables_set; | |
288 | ||
289 | /* Adds a variable to variables_set. */ | |
290 | static void | |
291 | note_variable (const char *var_ptr, size_t var_len) | |
292 | { | |
293 | char *string = xmalloc (var_len + 1); | |
294 | memcpy (string, var_ptr, var_len); | |
295 | string[var_len] = '\0'; | |
296 | ||
297 | string_list_append (&variables_set, string); | |
298 | } | |
299 | ||
300 | /* Stores the variables occurring in the string in variables_set. */ | |
301 | static void | |
302 | note_variables (const char *string) | |
303 | { | |
304 | string_list_init (&variables_set); | |
305 | find_variables (string, ¬e_variable); | |
306 | string_list_sort (&variables_set); | |
307 | } | |
308 | ||
309 | ||
310 | static int | |
311 | do_getc (void) | |
312 | { | |
313 | int c = getc (stdin); | |
314 | ||
315 | if (c == EOF) | |
316 | { | |
317 | if (ferror (stdin)) | |
318 | error ("error while reading standard input"); | |
319 | } | |
320 | ||
321 | return c; | |
322 | } | |
323 | ||
324 | static inline void | |
325 | do_ungetc (int c) | |
326 | { | |
327 | if (c != EOF) | |
328 | ungetc (c, stdin); | |
329 | } | |
330 | ||
331 | /* Copies stdin to stdout, performing substitutions. */ | |
332 | static void | |
333 | subst_from_stdin (void) | |
334 | { | |
335 | static char *buffer; | |
336 | static size_t bufmax; | |
337 | static size_t buflen; | |
338 | int c; | |
339 | ||
340 | for (;;) | |
341 | { | |
342 | c = do_getc (); | |
343 | if (c == EOF) | |
344 | break; | |
345 | /* Look for $VARIABLE or ${VARIABLE}. */ | |
346 | if (c == '$') | |
347 | { | |
348 | unsigned short int opening_brace = 0; | |
349 | unsigned short int closing_brace = 0; | |
350 | ||
351 | c = do_getc (); | |
352 | if (c == '{') | |
353 | { | |
354 | opening_brace = 1; | |
355 | c = do_getc (); | |
356 | } | |
357 | if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') | |
358 | { | |
359 | unsigned short int valid; | |
360 | ||
361 | /* Accumulate the VARIABLE in buffer. */ | |
362 | buflen = 0; | |
363 | do | |
364 | { | |
365 | if (buflen >= bufmax) | |
366 | { | |
367 | bufmax = 2 * bufmax + 10; | |
368 | buffer = xrealloc (buffer, bufmax); | |
369 | } | |
370 | buffer[buflen++] = c; | |
371 | ||
372 | c = do_getc (); | |
373 | } | |
374 | while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') | |
375 | || (c >= '0' && c <= '9') || c == '_'); | |
376 | ||
377 | if (opening_brace) | |
378 | { | |
379 | if (c == '}') | |
380 | { | |
381 | closing_brace = 1; | |
382 | valid = 1; | |
383 | } | |
384 | else | |
385 | { | |
386 | valid = 0; | |
387 | do_ungetc (c); | |
388 | } | |
389 | } | |
390 | else | |
391 | { | |
392 | valid = 1; | |
393 | do_ungetc (c); | |
394 | } | |
395 | ||
396 | if (valid) | |
397 | { | |
398 | /* Terminate the variable in the buffer. */ | |
399 | if (buflen >= bufmax) | |
400 | { | |
401 | bufmax = 2 * bufmax + 10; | |
402 | buffer = xrealloc (buffer, bufmax); | |
403 | } | |
404 | buffer[buflen] = '\0'; | |
405 | ||
406 | /* Test whether the variable shall be substituted. */ | |
407 | if (!all_variables | |
408 | && !sorted_string_list_member (&variables_set, buffer)) | |
409 | valid = 0; | |
410 | } | |
411 | ||
412 | if (valid) | |
413 | { | |
414 | /* Substitute the variable's value from the environment. */ | |
415 | const char *env_value = getenv (buffer); | |
416 | ||
417 | if (env_value != NULL) | |
418 | fputs (env_value, stdout); | |
419 | } | |
420 | else | |
421 | { | |
422 | /* Perform no substitution at all. Since the buffered input | |
423 | contains no other '$' than at the start, we can just | |
424 | output all the buffered contents. */ | |
425 | putchar ('$'); | |
426 | if (opening_brace) | |
427 | putchar ('{'); | |
428 | fwrite (buffer, buflen, 1, stdout); | |
429 | if (closing_brace) | |
430 | putchar ('}'); | |
431 | } | |
432 | } | |
433 | else | |
434 | { | |
435 | do_ungetc (c); | |
436 | putchar ('$'); | |
437 | if (opening_brace) | |
438 | putchar ('{'); | |
439 | } | |
440 | } | |
441 | else | |
442 | putchar (c); | |
443 | } | |
444 | } |