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#include "qemu/osdep.h"
#include "qemu/queue.h"
#include "qemu/envlist.h"
struct envlist_entry {
const char *ev_var; /* actual env value */
QLIST_ENTRY(envlist_entry) ev_link;
};
struct envlist {
QLIST_HEAD(, envlist_entry) el_entries; /* actual entries */
size_t el_count; /* number of entries */
};
/*
* Allocates new envlist and returns pointer to it.
*/
envlist_t *
envlist_create(void)
{
envlist_t *envlist;
envlist = g_malloc(sizeof(*envlist));
QLIST_INIT(&envlist->el_entries);
envlist->el_count = 0;
return (envlist);
}
/*
* Releases given envlist and its entries.
*/
void
envlist_free(envlist_t *envlist)
{
struct envlist_entry *entry;
assert(envlist != NULL);
while (envlist->el_entries.lh_first != NULL) {
entry = envlist->el_entries.lh_first;
QLIST_REMOVE(entry, ev_link);
g_free((char *)entry->ev_var);
g_free(entry);
}
g_free(envlist);
}
/*
* Sets environment value to envlist in similar manner
* than putenv(3).
*
* Returns 0 in success, errno otherwise.
*/
int
envlist_setenv(envlist_t *envlist, const char *env)
{
struct envlist_entry *entry = NULL;
const char *eq_sign;
size_t envname_len;
if ((envlist == NULL) || (env == NULL))
return (EINVAL);
/* find out first equals sign in given env */
if ((eq_sign = strchr(env, '=')) == NULL)
return (EINVAL);
envname_len = eq_sign - env + 1;
/*
* If there already exists variable with given name
* we remove and release it before allocating a whole
* new entry.
*/
for (entry = envlist->el_entries.lh_first; entry != NULL;
entry = entry->ev_link.le_next) {
if (strncmp(entry->ev_var, env, envname_len) == 0)
break;
}
if (entry != NULL) {
QLIST_REMOVE(entry, ev_link);
g_free((char *)entry->ev_var);
g_free(entry);
} else {
envlist->el_count++;
}
entry = g_malloc(sizeof(*entry));
entry->ev_var = g_strdup(env);
QLIST_INSERT_HEAD(&envlist->el_entries, entry, ev_link);
return (0);
}
/*
* Removes given env value from envlist in similar manner
* than unsetenv(3). Returns 0 in success, errno otherwise.
*/
int
envlist_unsetenv(envlist_t *envlist, const char *env)
{
struct envlist_entry *entry;
size_t envname_len;
if ((envlist == NULL) || (env == NULL))
return (EINVAL);
/* env is not allowed to contain '=' */
if (strchr(env, '=') != NULL)
return (EINVAL);
/*
* Find out the requested entry and remove
* it from the list.
*/
envname_len = strlen(env);
for (entry = envlist->el_entries.lh_first; entry != NULL;
entry = entry->ev_link.le_next) {
if (strncmp(entry->ev_var, env, envname_len) == 0)
break;
}
if (entry != NULL) {
QLIST_REMOVE(entry, ev_link);
g_free((char *)entry->ev_var);
g_free(entry);
envlist->el_count--;
}
return (0);
}
/*
* Returns given envlist as array of strings (in same form that
* global variable environ is). Caller must free returned memory
* by calling g_free for each element and the array.
* Returned array and given envlist are not related (no common
* references).
*
* If caller provides count pointer, number of items in array is
* stored there.
*/
char **
envlist_to_environ(const envlist_t *envlist, size_t *count)
{
struct envlist_entry *entry;
char **env, **penv;
penv = env = g_new(char *, envlist->el_count + 1);
for (entry = envlist->el_entries.lh_first; entry != NULL;
entry = entry->ev_link.le_next) {
*(penv++) = g_strdup(entry->ev_var);
}
*penv = NULL; /* NULL terminate the list */
if (count != NULL)
*count = envlist->el_count;
return (env);
}
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