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shell_var.c 11 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_nocasestr(name, "__prefix") == name) {
  86. int idx = 0;
  87. int pnum = 0;
  88. pnum = lub_argv_wordcount(clish_command__get_name(this->cmd)) -
  89. lub_argv_wordcount(clish_command__get_name(
  90. clish_command__get_cmd(this->cmd)));
  91. idx = atoi(name + strlen("__prefix"));
  92. if (idx < pnum) {
  93. lub_argv_t *argv = lub_argv_new(
  94. clish_command__get_name(this->cmd), 0);
  95. result = lub_string_dup(lub_argv__get_arg(argv, idx));
  96. lub_argv_delete(argv);
  97. }
  98. }
  99. return result;
  100. }
  101. /*--------------------------------------------------------- */
  102. static char *find_var(const char *name, lub_bintree_t *tree, clish_context_t *context)
  103. {
  104. clish_var_t *var = lub_bintree_find(tree, name);
  105. clish_action_t *action;
  106. char *value;
  107. char *script;
  108. bool_t dynamic;
  109. char *res = NULL;
  110. if (!var)
  111. return NULL;
  112. /* Try to get saved value for static var */
  113. dynamic = clish_var__get_dynamic(var);
  114. if (!dynamic) {
  115. char *saved = clish_var__get_saved(var);
  116. if (saved)
  117. return lub_string_dup(saved);
  118. }
  119. /* Try to expand value field */
  120. value = clish_var__get_value(var);
  121. if (value)
  122. res = clish_shell_expand(value, SHELL_VAR_NONE, context);
  123. /* Try to execute ACTION */
  124. if (!res) {
  125. action = clish_var__get_action(var);
  126. script = clish_action__get_script(action);
  127. if (script) {
  128. char *out = NULL;
  129. if (clish_shell_exec_action(action, context, &out)) {
  130. lub_string_free(out);
  131. return NULL;
  132. }
  133. res = out;
  134. }
  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. /*--------------------------------------------------------- */
  155. /*
  156. * return the next segment of text from the provided string
  157. * segments are delimited by variables within the string.
  158. */
  159. static char *expand_nextsegment(const char **string, const char *escape_chars,
  160. clish_context_t *this)
  161. {
  162. const char *p = *string;
  163. char *result = NULL;
  164. size_t len = 0;
  165. if (!p)
  166. return NULL;
  167. if (*p && (p[0] == '$') && (p[1] == '{')) {
  168. /* start of a variable */
  169. const char *tmp;
  170. p += 2;
  171. tmp = p;
  172. /*
  173. * find the end of the variable
  174. */
  175. while (*p && p++[0] != '}')
  176. len++;
  177. /* ignore non-terminated variables */
  178. if (p[-1] == '}') {
  179. bool_t valid = BOOL_FALSE;
  180. char *text, *q;
  181. char *saveptr;
  182. /* get the variable text */
  183. text = lub_string_dupn(tmp, len);
  184. /*
  185. * tokenise this INTO ':' separated words
  186. * and either expand or duplicate into the result string.
  187. * Only return a result if at least
  188. * of the words is an expandable variable
  189. */
  190. for (q = strtok_r(text, ":", &saveptr);
  191. q; q = strtok_r(NULL, ":", &saveptr)) {
  192. char *var;
  193. int mod_quote = 0; /* quote modifier */
  194. int mod_esc = 0; /* escape modifier */
  195. char *space;
  196. /* Search for modifiers */
  197. while (*q && !isalpha(*q)) {
  198. if ('#' == *q) {
  199. mod_quote = 1;
  200. mod_esc = 1;
  201. } else if ('\\' == *q)
  202. mod_esc = 1;
  203. else
  204. break;
  205. q++;
  206. }
  207. /* Get clean variable value */
  208. var = clish_shell_expand_var(q, this);
  209. if (!var) {
  210. lub_string_cat(&result, q);
  211. continue;
  212. }
  213. valid = BOOL_TRUE;
  214. /* Quoting */
  215. if (mod_quote)
  216. space = strchr(var, ' ');
  217. if (mod_quote && space)
  218. lub_string_cat(&result, "\"");
  219. /* Internal escaping */
  220. if (mod_esc) {
  221. char *tstr = lub_string_encode(var,
  222. lub_string_esc_quoted);
  223. lub_string_free(var);
  224. var = tstr;
  225. }
  226. /* Escape special chars */
  227. if (escape_chars) {
  228. char *tstr = lub_string_encode(var, escape_chars);
  229. lub_string_free(var);
  230. var = tstr;
  231. }
  232. /* copy the expansion or the raw word */
  233. lub_string_cat(&result, var);
  234. /* Quoting */
  235. if (mod_quote && space)
  236. lub_string_cat(&result, "\"");
  237. lub_string_free(var);
  238. }
  239. if (!valid) {
  240. /* not a valid variable expansion */
  241. lub_string_free(result);
  242. result = lub_string_dup("");
  243. }
  244. /* finished with the variable text */
  245. lub_string_free(text);
  246. }
  247. } else {
  248. /* find the start of a variable */
  249. while (*p) {
  250. if ((p[0] == '$') && (p[1] == '{'))
  251. break;
  252. len++;
  253. p++;
  254. }
  255. if (len > 0)
  256. result = lub_string_dupn(*string, len);
  257. }
  258. /* move the string pointer on for next time... */
  259. *string = p;
  260. return result;
  261. }
  262. /*--------------------------------------------------------- */
  263. /*
  264. * This function builds a dynamic string based on that provided
  265. * subtituting each occurance of a "${FRED}" type variable sub-string
  266. * with the appropriate value.
  267. */
  268. char *clish_shell_expand(const char *str, clish_shell_var_t vtype, clish_context_t *context)
  269. {
  270. char *seg, *result = NULL;
  271. const char *escape_chars = NULL;
  272. const clish_command_t *cmd = context->cmd;
  273. /* Escape special characters */
  274. if (SHELL_VAR_REGEX == vtype) {
  275. if (cmd)
  276. escape_chars = clish_command__get_regex_chars(cmd);
  277. if (!escape_chars)
  278. escape_chars = lub_string_esc_regex;
  279. } else if (SHELL_VAR_ACTION == vtype) {
  280. if (cmd)
  281. escape_chars = clish_command__get_escape_chars(cmd);
  282. if (!escape_chars)
  283. escape_chars = lub_string_esc_default;
  284. }
  285. /* read each segment and extend the result */
  286. while ((seg = expand_nextsegment(&str, escape_chars, context))) {
  287. lub_string_cat(&result, seg);
  288. lub_string_free(seg);
  289. }
  290. return result;
  291. }
  292. /*--------------------------------------------------------- */
  293. char *clish_shell__get_params(clish_context_t *context)
  294. {
  295. clish_pargv_t *pargv = context->pargv;
  296. char *line = NULL;
  297. unsigned i, cnt;
  298. const clish_param_t *param;
  299. const clish_parg_t *parg;
  300. char *request = NULL;
  301. if (!pargv)
  302. return NULL;
  303. cnt = clish_pargv__get_count(pargv);
  304. for (i = 0; i < cnt; i++) {
  305. param = clish_pargv__get_param(pargv, i);
  306. if (clish_param__get_hidden(param))
  307. continue;
  308. parg = clish_pargv__get_parg(pargv, i);
  309. if (request)
  310. lub_string_cat(&request, " ");
  311. lub_string_cat(&request, "${#");
  312. lub_string_cat(&request, clish_parg__get_name(parg));
  313. lub_string_cat(&request, "}");
  314. }
  315. line = clish_shell_expand(request, SHELL_VAR_NONE, context);
  316. lub_string_free(request);
  317. return line;
  318. }
  319. /*--------------------------------------------------------- */
  320. static char *internal_get_line(clish_context_t *context, int cmd_type)
  321. {
  322. const clish_command_t *cmd = context->cmd;
  323. clish_pargv_t *pargv = context->pargv;
  324. char *line = NULL;
  325. char *params = NULL;
  326. if (0 == cmd_type) /* __cmd */
  327. lub_string_cat(&line, clish_command__get_name(
  328. clish_command__get_cmd(cmd)));
  329. else /* __full_cmd */
  330. lub_string_cat(&line, clish_command__get_name(cmd));
  331. if (!pargv)
  332. return line;
  333. params = clish_shell__get_params(context);
  334. if (params) {
  335. lub_string_cat(&line, " ");
  336. lub_string_cat(&line, params);
  337. }
  338. lub_string_free(params);
  339. return line;
  340. }
  341. /*--------------------------------------------------------- */
  342. char *clish_shell__get_line(clish_context_t *context)
  343. {
  344. return internal_get_line(context, 0); /* __cmd */
  345. }
  346. /*--------------------------------------------------------- */
  347. char *clish_shell__get_full_line(clish_context_t *context)
  348. {
  349. return internal_get_line(context, 1); /* __full_cmd */
  350. }
  351. /*--------------------------------------------------------- */
  352. char *clish_shell_expand_var(const char *name, clish_context_t *context)
  353. {
  354. clish_shell_t *this;
  355. const clish_command_t *cmd;
  356. clish_pargv_t *pargv;
  357. const char *tmp = NULL;
  358. char *string = NULL;
  359. assert(name);
  360. if (!context)
  361. return NULL;
  362. this = context->shell;
  363. cmd = context->cmd;
  364. pargv = context->pargv;
  365. /* try and substitute a parameter value */
  366. if (pargv) {
  367. const clish_parg_t *parg = clish_pargv_find_arg(pargv, name);
  368. if (parg)
  369. tmp = clish_parg__get_value(parg);
  370. }
  371. /* try and substitute the param's default */
  372. if (!tmp && cmd)
  373. tmp = clish_paramv_find_default(
  374. clish_command__get_paramv(cmd), name);
  375. /* try and substitute a viewId variable */
  376. if (!tmp && this)
  377. tmp = string = find_viewid_var(name, context);
  378. /* try and substitute context fixed variable */
  379. if (!tmp)
  380. tmp = string = find_context_var(name, context);
  381. /* try and substitute a global var value */
  382. if (!tmp && this)
  383. tmp = string = find_global_var(name, context);
  384. /* get the contents of an environment variable */
  385. if (!tmp)
  386. tmp = getenv(name);
  387. if (string)
  388. return string;
  389. return lub_string_dup(tmp);
  390. }
  391. /*----------------------------------------------------------- */