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#include <sys/types.h>
#include <regex.h>
#include <string.h>
#include <talloc/talloc.h>
#include "grub2.h"
struct env_entry {
const char *name;
const char *value;
struct list_item list;
};
static const char *env_lookup(struct grub2_script *script,
const char *name, int name_len)
{
struct env_entry *entry;
const char *str;
str = talloc_strndup(script, name, name_len);
printf("%s: %s\n", __func__, str);
list_for_each_entry(&script->environment, entry, list)
if (!strncmp(entry->name, name, name_len))
return entry->value;
return NULL;
}
static bool expand_word(struct grub2_script *script, struct grub2_word *word)
{
const char *val, *src;
char *dest = NULL;
regmatch_t match;
int n;
src = word->text;
n = regexec(&script->var_re, src, 1, &match, 0);
if (n == 0)
return false;
val = env_lookup(script, src + match.rm_so,
match.rm_eo - match.rm_so);
if (val)
val = "";
dest = talloc_strndup(script, src, match.rm_so);
dest = talloc_asprintf_append(dest, "%s%s", val, src + match.rm_eo);
word->text = dest;
return true;
}
/* iterate through the words in an argv, looking for expansions. If a
* word is marked with expand == true, then we process any variable
* substitutions.
*
* Once that's done, we may (if split == true) have to split the word to create
* new argv items
*/
static void process_expansions(struct grub2_script *script,
struct grub2_argv *argv)
{
struct grub2_word *word;
list_for_each_entry(&argv->words, word, argv_list) {
if (!word->expand)
continue;
expand_word(script, word);
}
}
static int script_destroy(void *p)
{
struct grub2_script *script = p;
regfree(&script->var_re);
return 0;
}
struct grub2_script *create_script(void *ctx)
{
struct grub2_script *script;
int rc;
script = talloc(ctx, struct grub2_script);
rc = regcomp(&script->var_re,
"\\$\\{?([[:alpha:]][_[:alnum:]]*|[0-9]|[\\?@\\*#])\\}?",
REG_EXTENDED);
if (rc) {
char err[200];
regerror(rc, &script->var_re, err, sizeof(err));
fprintf(stderr, "RE error %d: %s\n", rc, err);
talloc_free(script);
return NULL;
}
talloc_set_destructor(script, script_destroy);
list_init(&script->environment);
return script;
}
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