180 lines
4.1 KiB
C
180 lines
4.1 KiB
C
#define _POSIX_C_SOURCE 200809L
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#include <ctype.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "../utils/ast/ast.h"
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#include "../utils/hash_map/hash_map.h"
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#include "../utils/string_utils/string_utils.h"
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#include "../utils/vars/vars.h"
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static bool is_var_start_char(char c)
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{
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return isalpha(c) || c == '_';
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}
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static bool is_var_char(char c)
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{
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return isalnum(c) || c == '_';
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}
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static bool is_special_var_char(char c)
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{
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return c == '@' || c == '*' || c == '?' || c == '$' || isdigit(c)
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|| c == '#';
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}
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size_t parse_var_name(char *str, char **res)
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{
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char *brace = NULL;
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size_t i = 1; // skip the '$'
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if (str[i] == '{' && str[i + 1] != 0 && str[i + 1] != '}')
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{
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if (is_special_var_char(str[i + 1]) && str[i + 2] == '}')
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{
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// Special variable like ${1}, ${?}
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*res = strndup(str + i + 1, 1);
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return 4; // length of ${X}
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}
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brace = str + i;
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i++; // skip the '{'
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}
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else if (is_special_var_char(str[i]))
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{
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*res = strndup(str + i, 1);
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return 2; // length of $X
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}
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if (!is_var_start_char(str[i]))
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{
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// Not a valid variable start
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*res = NULL;
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return 0;
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}
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while (1)
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{
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if (str[i] == '}' && *brace == '{')
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{
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*res = strndup(str + 2, i - 2);
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return i + 1;
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}
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else if (!is_var_char(str[i]))
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{
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if (brace != NULL)
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{
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// Missing closing '}'
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*res = NULL;
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return 0;
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}
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break;
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}
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i++;
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}
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*res = strndup(str + 1, i - 1);
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return i;
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}
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static bool expand_var(char **str, size_t pos, const struct hash_map *vars)
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{
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char *var_name = NULL;
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size_t r = parse_var_name(*str + pos, &var_name);
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if (r > 0 && var_name != NULL)
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{
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char *value;
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char rnd_str[10]; // max 5 digits + null terminator
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if (strcmp(var_name, "RANDOM") == 0)
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{
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short rnd = short_random();
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snprintf(rnd_str, 10, "%d", rnd);
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value = rnd_str;
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}
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else
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{
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value = get_var_or_env(vars, var_name);
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if (value == NULL)
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// Undefined variable: expand to empty string
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value = "";
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}
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char *p = insert_into(*str, value, pos, r);
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free(var_name);
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if (p == NULL)
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{
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// error: insertion failed
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return false;
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}
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*str = p;
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return true;
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}
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return false;
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}
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struct ast_command *expand(struct ast_command *command,
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const struct hash_map *vars)
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{
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if (command == NULL)
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return NULL;
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char *str;
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size_t len;
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bool in_quotes;
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struct list *l = command->command;
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while (l != NULL)
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{
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in_quotes = false;
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str = (char *)l->data;
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len = strlen(str);
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for (size_t i = 0; str[i] != 0; i++)
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{
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if (str[i] == '\'')
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{
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// remove quote
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in_quotes = !in_quotes;
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memmove(str + i, str + i + 1, strlen(str + i + 1) + 1);
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i--;
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}
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else if (in_quotes)
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{
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continue; // do nothing
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}
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else if (str[i] == '$' && str[i + 1] != 0 && !isspace(str[i + 1]))
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{
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// variable expansion
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bool r = expand_var(&str, i, vars);
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if (r == false || str == NULL)
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return NULL;
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i--; // -1 because loop will increment i
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}
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}
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if (in_quotes)
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{
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// error: quote not closed
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fprintf(stderr, "Error: quote not closed in string: %s\n", str);
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return NULL;
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}
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if (len != strlen(str))
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{
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char *new_str = realloc(str, strlen(str) + 1);
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if (new_str == NULL)
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{
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// error: realloc fail
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return NULL;
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}
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l->data = new_str;
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}
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l = l->next;
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}
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return command;
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}
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