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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"); | |
76 | /* | |
77 | all_variables = 1; | |
78 | subst_from_stdin (); | |
79 | */ | |
80 | case 2: | |
81 | /* echo '$foo and $bar' | git sh-i18n--envsubst --variables '$foo and $bar' */ | |
82 | all_variables = 0; | |
83 | note_variables (argv[1]); | |
84 | subst_from_stdin (); | |
85 | break; | |
86 | case 3: | |
87 | /* git sh-i18n--envsubst --variables '$foo and $bar' */ | |
88 | if (strcmp(argv[1], "--variables")) | |
89 | error ("first argument must be --variables when two are given"); | |
600a6a68 | 90 | /* show_variables = 1; */ |
ba67aaf2 ÆAB |
91 | print_variables (argv[2]); |
92 | break; | |
93 | default: | |
94 | error ("too many arguments"); | |
95 | break; | |
96 | } | |
97 | ||
98 | /* Close standard error. This is simpler than fwriteerror_no_ebadf, because | |
99 | upon failure we don't need an errno - all we can do at this point is to | |
100 | set an exit status. */ | |
101 | errno = 0; | |
102 | if (ferror (stderr) || fflush (stderr)) | |
103 | { | |
104 | fclose (stderr); | |
105 | exit (EXIT_FAILURE); | |
106 | } | |
107 | if (fclose (stderr) && errno != EBADF) | |
108 | exit (EXIT_FAILURE); | |
109 | ||
110 | exit (EXIT_SUCCESS); | |
111 | } | |
112 | ||
113 | /* Parse the string and invoke the callback each time a $VARIABLE or | |
114 | ${VARIABLE} construct is seen, where VARIABLE is a nonempty sequence | |
115 | of ASCII alphanumeric/underscore characters, starting with an ASCII | |
116 | alphabetic/underscore character. | |
117 | We allow only ASCII characters, to avoid dependencies w.r.t. the current | |
118 | encoding: While "${\xe0}" looks like a variable access in ISO-8859-1 | |
119 | encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030, | |
120 | SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these | |
121 | encodings. */ | |
122 | static void | |
123 | find_variables (const char *string, | |
124 | void (*callback) (const char *var_ptr, size_t var_len)) | |
125 | { | |
126 | for (; *string != '\0';) | |
127 | if (*string++ == '$') | |
128 | { | |
129 | const char *variable_start; | |
130 | const char *variable_end; | |
131 | unsigned short int valid; | |
132 | char c; | |
133 | ||
134 | if (*string == '{') | |
135 | string++; | |
136 | ||
137 | variable_start = string; | |
138 | c = *string; | |
139 | if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') | |
140 | { | |
141 | do | |
142 | c = *++string; | |
143 | while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') | |
144 | || (c >= '0' && c <= '9') || c == '_'); | |
145 | variable_end = string; | |
146 | ||
147 | if (variable_start[-1] == '{') | |
148 | { | |
149 | if (*string == '}') | |
150 | { | |
151 | string++; | |
152 | valid = 1; | |
153 | } | |
154 | else | |
155 | valid = 0; | |
156 | } | |
157 | else | |
158 | valid = 1; | |
159 | ||
160 | if (valid) | |
161 | callback (variable_start, variable_end - variable_start); | |
162 | } | |
163 | } | |
164 | } | |
165 | ||
166 | ||
167 | /* Print a variable to stdout, followed by a newline. */ | |
168 | static void | |
169 | print_variable (const char *var_ptr, size_t var_len) | |
170 | { | |
171 | fwrite (var_ptr, var_len, 1, stdout); | |
172 | putchar ('\n'); | |
173 | } | |
174 | ||
175 | /* Print the variables contained in STRING to stdout, each one followed by a | |
176 | newline. */ | |
177 | static void | |
178 | print_variables (const char *string) | |
179 | { | |
180 | find_variables (string, &print_variable); | |
181 | } | |
182 | ||
183 | ||
184 | /* Type describing list of immutable strings, | |
185 | implemented using a dynamic array. */ | |
186 | typedef struct string_list_ty string_list_ty; | |
187 | struct string_list_ty | |
188 | { | |
189 | const char **item; | |
190 | size_t nitems; | |
191 | size_t nitems_max; | |
192 | }; | |
193 | ||
194 | /* Initialize an empty list of strings. */ | |
195 | static inline void | |
196 | string_list_init (string_list_ty *slp) | |
197 | { | |
198 | slp->item = NULL; | |
199 | slp->nitems = 0; | |
200 | slp->nitems_max = 0; | |
201 | } | |
202 | ||
203 | /* Append a single string to the end of a list of strings. */ | |
204 | static inline void | |
205 | string_list_append (string_list_ty *slp, const char *s) | |
206 | { | |
207 | /* Grow the list. */ | |
208 | if (slp->nitems >= slp->nitems_max) | |
209 | { | |
210 | size_t nbytes; | |
211 | ||
212 | slp->nitems_max = slp->nitems_max * 2 + 4; | |
213 | nbytes = slp->nitems_max * sizeof (slp->item[0]); | |
214 | slp->item = (const char **) xrealloc (slp->item, nbytes); | |
215 | } | |
216 | ||
217 | /* Add the string to the end of the list. */ | |
218 | slp->item[slp->nitems++] = s; | |
219 | } | |
220 | ||
221 | /* Compare two strings given by reference. */ | |
222 | static int | |
223 | cmp_string (const void *pstr1, const void *pstr2) | |
224 | { | |
225 | const char *str1 = *(const char **)pstr1; | |
226 | const char *str2 = *(const char **)pstr2; | |
227 | ||
228 | return strcmp (str1, str2); | |
229 | } | |
230 | ||
231 | /* Sort a list of strings. */ | |
232 | static inline void | |
233 | string_list_sort (string_list_ty *slp) | |
234 | { | |
235 | if (slp->nitems > 0) | |
236 | qsort (slp->item, slp->nitems, sizeof (slp->item[0]), cmp_string); | |
237 | } | |
238 | ||
239 | /* Test whether a string list contains a given string. */ | |
240 | static inline int | |
241 | string_list_member (const string_list_ty *slp, const char *s) | |
242 | { | |
243 | size_t j; | |
244 | ||
245 | for (j = 0; j < slp->nitems; ++j) | |
246 | if (strcmp (slp->item[j], s) == 0) | |
247 | return 1; | |
248 | return 0; | |
249 | } | |
250 | ||
251 | /* Test whether a sorted string list contains a given string. */ | |
252 | static int | |
253 | sorted_string_list_member (const string_list_ty *slp, const char *s) | |
254 | { | |
255 | size_t j1, j2; | |
256 | ||
257 | j1 = 0; | |
258 | j2 = slp->nitems; | |
259 | if (j2 > 0) | |
260 | { | |
261 | /* Binary search. */ | |
262 | while (j2 - j1 > 1) | |
263 | { | |
264 | /* Here we know that if s is in the list, it is at an index j | |
265 | with j1 <= j < j2. */ | |
266 | size_t j = (j1 + j2) >> 1; | |
267 | int result = strcmp (slp->item[j], s); | |
268 | ||
269 | if (result > 0) | |
270 | j2 = j; | |
271 | else if (result == 0) | |
272 | return 1; | |
273 | else | |
274 | j1 = j + 1; | |
275 | } | |
276 | if (j2 > j1) | |
277 | if (strcmp (slp->item[j1], s) == 0) | |
278 | return 1; | |
279 | } | |
280 | return 0; | |
281 | } | |
282 | ||
283 | ||
284 | /* Set of variables on which to perform substitution. | |
285 | Used only if !all_variables. */ | |
286 | static string_list_ty variables_set; | |
287 | ||
288 | /* Adds a variable to variables_set. */ | |
289 | static void | |
290 | note_variable (const char *var_ptr, size_t var_len) | |
291 | { | |
292 | char *string = xmalloc (var_len + 1); | |
293 | memcpy (string, var_ptr, var_len); | |
294 | string[var_len] = '\0'; | |
295 | ||
296 | string_list_append (&variables_set, string); | |
297 | } | |
298 | ||
299 | /* Stores the variables occurring in the string in variables_set. */ | |
300 | static void | |
301 | note_variables (const char *string) | |
302 | { | |
303 | string_list_init (&variables_set); | |
304 | find_variables (string, ¬e_variable); | |
305 | string_list_sort (&variables_set); | |
306 | } | |
307 | ||
308 | ||
309 | static int | |
310 | do_getc (void) | |
311 | { | |
312 | int c = getc (stdin); | |
313 | ||
314 | if (c == EOF) | |
315 | { | |
316 | if (ferror (stdin)) | |
317 | error ("error while reading standard input"); | |
318 | } | |
319 | ||
320 | return c; | |
321 | } | |
322 | ||
323 | static inline void | |
324 | do_ungetc (int c) | |
325 | { | |
326 | if (c != EOF) | |
327 | ungetc (c, stdin); | |
328 | } | |
329 | ||
330 | /* Copies stdin to stdout, performing substitutions. */ | |
331 | static void | |
332 | subst_from_stdin (void) | |
333 | { | |
334 | static char *buffer; | |
335 | static size_t bufmax; | |
336 | static size_t buflen; | |
337 | int c; | |
338 | ||
339 | for (;;) | |
340 | { | |
341 | c = do_getc (); | |
342 | if (c == EOF) | |
343 | break; | |
344 | /* Look for $VARIABLE or ${VARIABLE}. */ | |
345 | if (c == '$') | |
346 | { | |
347 | unsigned short int opening_brace = 0; | |
348 | unsigned short int closing_brace = 0; | |
349 | ||
350 | c = do_getc (); | |
351 | if (c == '{') | |
352 | { | |
353 | opening_brace = 1; | |
354 | c = do_getc (); | |
355 | } | |
356 | if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') | |
357 | { | |
358 | unsigned short int valid; | |
359 | ||
360 | /* Accumulate the VARIABLE in buffer. */ | |
361 | buflen = 0; | |
362 | do | |
363 | { | |
364 | if (buflen >= bufmax) | |
365 | { | |
366 | bufmax = 2 * bufmax + 10; | |
367 | buffer = xrealloc (buffer, bufmax); | |
368 | } | |
369 | buffer[buflen++] = c; | |
370 | ||
371 | c = do_getc (); | |
372 | } | |
373 | while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') | |
374 | || (c >= '0' && c <= '9') || c == '_'); | |
375 | ||
376 | if (opening_brace) | |
377 | { | |
378 | if (c == '}') | |
379 | { | |
380 | closing_brace = 1; | |
381 | valid = 1; | |
382 | } | |
383 | else | |
384 | { | |
385 | valid = 0; | |
386 | do_ungetc (c); | |
387 | } | |
388 | } | |
389 | else | |
390 | { | |
391 | valid = 1; | |
392 | do_ungetc (c); | |
393 | } | |
394 | ||
395 | if (valid) | |
396 | { | |
397 | /* Terminate the variable in the buffer. */ | |
398 | if (buflen >= bufmax) | |
399 | { | |
400 | bufmax = 2 * bufmax + 10; | |
401 | buffer = xrealloc (buffer, bufmax); | |
402 | } | |
403 | buffer[buflen] = '\0'; | |
404 | ||
405 | /* Test whether the variable shall be substituted. */ | |
406 | if (!all_variables | |
407 | && !sorted_string_list_member (&variables_set, buffer)) | |
408 | valid = 0; | |
409 | } | |
410 | ||
411 | if (valid) | |
412 | { | |
413 | /* Substitute the variable's value from the environment. */ | |
414 | const char *env_value = getenv (buffer); | |
415 | ||
416 | if (env_value != NULL) | |
417 | fputs (env_value, stdout); | |
418 | } | |
419 | else | |
420 | { | |
421 | /* Perform no substitution at all. Since the buffered input | |
422 | contains no other '$' than at the start, we can just | |
423 | output all the buffered contents. */ | |
424 | putchar ('$'); | |
425 | if (opening_brace) | |
426 | putchar ('{'); | |
427 | fwrite (buffer, buflen, 1, stdout); | |
428 | if (closing_brace) | |
429 | putchar ('}'); | |
430 | } | |
431 | } | |
432 | else | |
433 | { | |
434 | do_ungetc (c); | |
435 | putchar ('$'); | |
436 | if (opening_brace) | |
437 | putchar ('{'); | |
438 | } | |
439 | } | |
440 | else | |
441 | putchar (c); | |
442 | } | |
443 | } |