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shell_var.c 12 KB

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  1. /*
  2. * shell_var.c
  3. */
  4. #include <stdlib.h>
  5. #include <assert.h>
  6. #include <string.h>
  7. #include <ctype.h>
  8. #include "lub/string.h"
  9. #include "private.h"
  10. /*----------------------------------------------------------- */
  11. /*
  12. * search the current viewid string for a variable
  13. */
  14. void clish_shell__expand_viewid(const char *viewid, lub_bintree_t *tree,
  15. clish_context_t *context)
  16. {
  17. char *expanded;
  18. char *q, *saveptr;
  19. expanded = clish_shell_expand(viewid, SHELL_VAR_NONE, context);
  20. if (!expanded)
  21. return;
  22. for (q = strtok_r(expanded, ";", &saveptr);
  23. q; q = strtok_r(NULL, ";", &saveptr)) {
  24. char *value;
  25. clish_var_t *var;
  26. value = strchr(q, '=');
  27. if (!value)
  28. continue;
  29. *value = '\0';
  30. value++;
  31. /* Create var instance */
  32. var = clish_var_new(q);
  33. lub_bintree_insert(tree, var);
  34. clish_var__set_value(var, value);
  35. }
  36. lub_string_free(expanded);
  37. }
  38. /*----------------------------------------------------------- */
  39. /*
  40. * expand context dependent fixed-name variables
  41. */
  42. static char *find_context_var(const char *name, clish_context_t *this)
  43. {
  44. char *result = NULL;
  45. clish_shell_t *shell = this->shell;
  46. if (!lub_string_nocasecmp(name, "_width")) {
  47. char tmp[5];
  48. snprintf(tmp, sizeof(tmp), "%u",
  49. tinyrl__get_width(shell->tinyrl));
  50. tmp[sizeof(tmp) - 1] = '\0';
  51. result = strdup(tmp);
  52. } else if (!lub_string_nocasecmp(name, "_height")) {
  53. char tmp[5];
  54. snprintf(tmp, sizeof(tmp), "%u",
  55. tinyrl__get_height(shell->tinyrl));
  56. tmp[sizeof(tmp) - 1] = '\0';
  57. result = strdup(tmp);
  58. } else if (!lub_string_nocasecmp(name, "_watchdog_timeout")) {
  59. char tmp[5];
  60. snprintf(tmp, sizeof(tmp), "%u", shell->wdog_timeout);
  61. tmp[sizeof(tmp) - 1] = '\0';
  62. result = strdup(tmp);
  63. } else if (!this->cmd) { /* The vars dependent on command */
  64. return NULL;
  65. } else if (!lub_string_nocasecmp(name, "_full_cmd")) {
  66. result = lub_string_dup(clish_command__get_name(this->cmd));
  67. } else if (!lub_string_nocasecmp(name, "_cmd")) {
  68. result = lub_string_dup(clish_command__get_name(
  69. clish_command__get_cmd(this->cmd)));
  70. } else if (!lub_string_nocasecmp(name, "_orig_cmd")) {
  71. result = lub_string_dup(clish_command__get_name(
  72. clish_command__get_orig(this->cmd)));
  73. } else if (!lub_string_nocasecmp(name, "_line")) {
  74. result = clish_shell__get_line(this);
  75. } else if (!lub_string_nocasecmp(name, "_full_line")) {
  76. result = clish_shell__get_full_line(this);
  77. } else if (!lub_string_nocasecmp(name, "_params")) {
  78. if (this->pargv)
  79. result = clish_shell__get_params(this);
  80. } else if (!lub_string_nocasecmp(name, "_interactive")) {
  81. if (clish_shell__get_interactive(this->shell))
  82. result = strdup("1");
  83. else
  84. result = strdup("0");
  85. } else if (!lub_string_nocasecmp(name, "_isatty")) {
  86. if (tinyrl__get_isatty(this->shell->tinyrl))
  87. result = strdup("1");
  88. else
  89. result = strdup("0");
  90. } else if (lub_string_nocasestr(name, "_prefix") == name) {
  91. int idx = 0;
  92. int pnum = 0;
  93. pnum = lub_argv_wordcount(clish_command__get_name(this->cmd)) -
  94. lub_argv_wordcount(clish_command__get_name(
  95. clish_command__get_cmd(this->cmd)));
  96. idx = atoi(name + strlen("_prefix"));
  97. if (idx < pnum) {
  98. lub_argv_t *argv = lub_argv_new(
  99. clish_command__get_name(this->cmd), 0);
  100. result = lub_string_dup(lub_argv__get_arg(argv, idx));
  101. lub_argv_delete(argv);
  102. }
  103. }
  104. return result;
  105. }
  106. /*--------------------------------------------------------- */
  107. static char *find_var(const char *name, lub_bintree_t *tree, clish_context_t *context)
  108. {
  109. clish_var_t *var = lub_bintree_find(tree, name);
  110. char *value;
  111. bool_t dynamic;
  112. char *res = NULL;
  113. if (!var)
  114. return NULL;
  115. /* Try to get saved value for static var */
  116. dynamic = clish_var__get_dynamic(var);
  117. if (!dynamic) {
  118. char *saved = clish_var__get_saved(var);
  119. if (saved)
  120. return lub_string_dup(saved);
  121. }
  122. /* Try to expand value field */
  123. value = clish_var__get_value(var);
  124. if (value)
  125. res = clish_shell_expand(value, SHELL_VAR_NONE, context);
  126. /* Try to execute ACTION */
  127. if (!res) {
  128. char *out = NULL;
  129. context->action = clish_var__get_action(var);
  130. if (clish_shell_exec_action(context, &out)) {
  131. lub_string_free(out);
  132. return NULL;
  133. }
  134. res = out;
  135. }
  136. /* Save value for static var */
  137. if (!dynamic && res)
  138. clish_var__set_saved(var, res);
  139. return res;
  140. }
  141. /*--------------------------------------------------------- */
  142. static char *find_global_var(const char *name, clish_context_t *context)
  143. {
  144. return find_var(name, &context->shell->var_tree, context);
  145. }
  146. /*--------------------------------------------------------- */
  147. static char *find_viewid_var(const char *name, clish_context_t *context)
  148. {
  149. int depth = clish_shell__get_depth(context->shell);
  150. if (depth < 0)
  151. return NULL;
  152. return find_var(name, &context->shell->pwdv[depth]->viewid, context);
  153. }
  154. static char * chardiff(const char *syms, const char *minus)
  155. {
  156. char *dst = malloc(strlen(syms) + 1);
  157. char *p = dst;
  158. const char *src;
  159. for (src = syms; *src; src++) {
  160. if (!strchr(minus, *src))
  161. *(p++) = *src;
  162. }
  163. *p = '\0';
  164. return dst;
  165. }
  166. /*--------------------------------------------------------- */
  167. /*
  168. * return the next segment of text from the provided string
  169. * segments are delimited by variables within the string.
  170. */
  171. static char *expand_nextsegment(const char **string, const char *escape_chars,
  172. clish_context_t *this)
  173. {
  174. const char *p = *string;
  175. char *result = NULL;
  176. size_t len = 0;
  177. if (!p)
  178. return NULL;
  179. if (*p && (p[0] == '$') && (p[1] == '{')) {
  180. /* start of a variable */
  181. const char *tmp;
  182. p += 2;
  183. tmp = p;
  184. /*
  185. * find the end of the variable
  186. */
  187. while (*p && p++[0] != '}')
  188. len++;
  189. /* ignore non-terminated variables */
  190. if (p[-1] == '}') {
  191. bool_t valid = BOOL_FALSE;
  192. char *text, *q;
  193. char *saveptr;
  194. /* get the variable text */
  195. text = lub_string_dupn(tmp, len);
  196. /*
  197. * tokenise this INTO ':' separated words
  198. * and either expand or duplicate into the result string.
  199. * Only return a result if at least
  200. * of the words is an expandable variable
  201. */
  202. for (q = strtok_r(text, ":", &saveptr);
  203. q; q = strtok_r(NULL, ":", &saveptr)) {
  204. char *var;
  205. int mod_quote = 0; /* quote modifier */
  206. int mod_esc = 0; /* internal escape modifier */
  207. int mod_esc_chars = 1; /* escaping */
  208. int mod_esc_dec = 0; /* remove internal chars from escaping */
  209. char *space;
  210. char *all_esc = NULL;
  211. /* Search for modifiers */
  212. while (*q && !isalpha(*q)) {
  213. if ('#' == *q) {
  214. mod_quote = 1;
  215. mod_esc = 1;
  216. } else if ('\\' == *q) {
  217. mod_esc = 1;
  218. } else if ('!' == *q) {
  219. mod_quote = 1;
  220. mod_esc = 1;
  221. mod_esc_chars = 0;
  222. } else if ('~' == *q) {
  223. mod_esc = 1;
  224. mod_esc_chars = 0;
  225. } else if (('_' == *q) && ('_' == *(q+1))) {
  226. mod_esc_dec = 1;
  227. q++;
  228. break;
  229. } else
  230. break;
  231. q++;
  232. }
  233. /* Get clean variable value */
  234. var = clish_shell_expand_var(q, this);
  235. if (!var) {
  236. lub_string_cat(&result, q);
  237. continue;
  238. }
  239. valid = BOOL_TRUE;
  240. /* Quoting */
  241. if (mod_quote)
  242. space = strchr(var, ' ');
  243. if (mod_quote && space)
  244. lub_string_cat(&result, "\"");
  245. /* Escape special chars */
  246. if (escape_chars && mod_esc_chars) {
  247. /* Remove internal esc from escape chars */
  248. if (mod_esc_dec)
  249. all_esc = chardiff(escape_chars,
  250. lub_string_esc_quoted);
  251. else
  252. all_esc = lub_string_dup(escape_chars);
  253. }
  254. /* Internal escaping */
  255. if (mod_esc)
  256. lub_string_cat(&all_esc,
  257. lub_string_esc_quoted);
  258. /* Real escaping */
  259. if (all_esc) {
  260. char *tstr = lub_string_encode(var,
  261. all_esc);
  262. lub_string_free(var);
  263. var = tstr;
  264. lub_string_free(all_esc);
  265. }
  266. /* copy the expansion or the raw word */
  267. lub_string_cat(&result, var);
  268. /* Quoting */
  269. if (mod_quote && space)
  270. lub_string_cat(&result, "\"");
  271. lub_string_free(var);
  272. }
  273. if (!valid) {
  274. /* not a valid variable expansion */
  275. lub_string_free(result);
  276. result = lub_string_dup("");
  277. }
  278. /* finished with the variable text */
  279. lub_string_free(text);
  280. }
  281. } else {
  282. /* find the start of a variable */
  283. while (*p) {
  284. if ((p[0] == '$') && (p[1] == '{'))
  285. break;
  286. len++;
  287. p++;
  288. }
  289. if (len > 0)
  290. result = lub_string_dupn(*string, len);
  291. }
  292. /* move the string pointer on for next time... */
  293. *string = p;
  294. return result;
  295. }
  296. /*--------------------------------------------------------- */
  297. /*
  298. * This function builds a dynamic string based on that provided
  299. * subtituting each occurance of a "${FRED}" type variable sub-string
  300. * with the appropriate value.
  301. */
  302. char *clish_shell_expand(const char *str, clish_shell_var_t vtype, clish_context_t *context)
  303. {
  304. char *seg, *result = NULL;
  305. const char *escape_chars = NULL;
  306. const clish_command_t *cmd = context->cmd;
  307. /* Escape special characters */
  308. if (SHELL_VAR_REGEX == vtype) {
  309. if (cmd)
  310. escape_chars = clish_command__get_regex_chars(cmd);
  311. if (!escape_chars)
  312. escape_chars = lub_string_esc_regex;
  313. } else if (SHELL_VAR_ACTION == vtype) {
  314. if (cmd)
  315. escape_chars = clish_command__get_escape_chars(cmd);
  316. if (!escape_chars)
  317. escape_chars = lub_string_esc_default;
  318. }
  319. /* read each segment and extend the result */
  320. while ((seg = expand_nextsegment(&str, escape_chars, context))) {
  321. lub_string_cat(&result, seg);
  322. lub_string_free(seg);
  323. }
  324. return result;
  325. }
  326. /*--------------------------------------------------------- */
  327. char *clish_shell__get_params(clish_context_t *context)
  328. {
  329. clish_pargv_t *pargv = context->pargv;
  330. char *line = NULL;
  331. unsigned i, cnt;
  332. const clish_param_t *param;
  333. const clish_parg_t *parg;
  334. char *request = NULL;
  335. if (!pargv)
  336. return NULL;
  337. cnt = clish_pargv__get_count(pargv);
  338. for (i = 0; i < cnt; i++) {
  339. param = clish_pargv__get_param(pargv, i);
  340. if (clish_param__get_hidden(param))
  341. continue;
  342. parg = clish_pargv__get_parg(pargv, i);
  343. if (request)
  344. lub_string_cat(&request, " ");
  345. lub_string_cat(&request, "${!");
  346. lub_string_cat(&request, clish_parg__get_name(parg));
  347. lub_string_cat(&request, "}");
  348. }
  349. line = clish_shell_expand(request, SHELL_VAR_NONE, context);
  350. lub_string_free(request);
  351. return line;
  352. }
  353. /*--------------------------------------------------------- */
  354. static char *internal_get_line(clish_context_t *context, int cmd_type)
  355. {
  356. const clish_command_t *cmd = context->cmd;
  357. clish_pargv_t *pargv = context->pargv;
  358. char *line = NULL;
  359. char *params = NULL;
  360. if (0 == cmd_type) /* __cmd */
  361. lub_string_cat(&line, clish_command__get_name(
  362. clish_command__get_cmd(cmd)));
  363. else /* __full_cmd */
  364. lub_string_cat(&line, clish_command__get_name(cmd));
  365. if (!pargv)
  366. return line;
  367. params = clish_shell__get_params(context);
  368. if (params) {
  369. lub_string_cat(&line, " ");
  370. lub_string_cat(&line, params);
  371. }
  372. lub_string_free(params);
  373. return line;
  374. }
  375. /*--------------------------------------------------------- */
  376. char *clish_shell__get_line(clish_context_t *context)
  377. {
  378. return internal_get_line(context, 0); /* __cmd */
  379. }
  380. /*--------------------------------------------------------- */
  381. char *clish_shell__get_full_line(clish_context_t *context)
  382. {
  383. return internal_get_line(context, 1); /* __full_cmd */
  384. }
  385. /*--------------------------------------------------------- */
  386. char *clish_shell_expand_var(const char *name, clish_context_t *context)
  387. {
  388. clish_shell_t *this;
  389. const clish_command_t *cmd;
  390. clish_pargv_t *pargv;
  391. const char *tmp = NULL;
  392. char *string = NULL;
  393. assert(name);
  394. if (!context)
  395. return NULL;
  396. this = context->shell;
  397. cmd = context->cmd;
  398. pargv = context->pargv;
  399. /* try and substitute a parameter value */
  400. if (pargv) {
  401. const clish_parg_t *parg = clish_pargv_find_arg(pargv, name);
  402. if (parg)
  403. tmp = clish_parg__get_value(parg);
  404. }
  405. /* try and substitute the param's default */
  406. if (!tmp && cmd)
  407. tmp = clish_paramv_find_default(
  408. clish_command__get_paramv(cmd), name);
  409. /* try and substitute a viewId variable */
  410. if (!tmp && this)
  411. tmp = string = find_viewid_var(name, context);
  412. /* try and substitute context fixed variable */
  413. if (!tmp)
  414. tmp = string = find_context_var(name, context);
  415. /* try and substitute a global var value */
  416. if (!tmp && this)
  417. tmp = string = find_global_var(name, context);
  418. /* get the contents of an environment variable */
  419. if (!tmp)
  420. tmp = getenv(name);
  421. if (string)
  422. return string;
  423. return lub_string_dup(tmp);
  424. }
  425. /*----------------------------------------------------------- */