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/*
20140215
20241208 - reformated using clang-format
Jan Mojzis
Public domain.
The 'newenv' library is used to execute process in completely new environment.
*/
#include <unistd.h>
#include "e.h"
#include "byte.h"
#include "str.h"
#include "purge.h"
#include "bug.h"
#include "env.h"
#include "trymlock.h"
#include "newenv.h"
#define NEWENV_LEN 128
#define NEWENV_SPACE 2048
static struct newenv {
char *e[NEWENV_LEN];
long long elen;
char es[NEWENV_SPACE];
long long eslen;
} n = {{0}, 0, {0}, 0};
/*
Remove sentitive data from allocated memory.
*/
void newenv_purge(void) {
purge(&n, sizeof n);
n.elen = NEWENV_LEN;
n.eslen = NEWENV_SPACE;
trymunlock(&n, sizeof n);
}
/*
Initialize newenv structure.
*/
void newenv_init(void) {
trymlock(&n, sizeof n);
purge(&n, sizeof n);
n.e[0] = 0;
n.elen = n.eslen = 0;
}
/*
The 'newenv_env/newenv_lowenv' function adds the variable into new environment.
The newenv_lowenv is limited to a half of the buffer-space.
*/
int newenv_env_(int x, const char *s, const char *t) {
long long slen, tlen, len, i;
if (!x || !s || !t) bug_inval();
if (n.elen < 0) bug_inval();
if (n.eslen < 0) bug_inval();
slen = str_len(s);
tlen = str_len(t);
len = slen + tlen + 2;
if (!n.elen) newenv_init();
for (i = 0; n.e[i]; ++i) {
if (str_start(n.e[i], s) && (n.e[i][slen] == '=')) {
n.e[i] = n.e[--n.elen];
break;
}
}
if (n.elen + 2 > NEWENV_LEN / x) {
errno = ENOMEM;
return 0;
}
if (n.eslen + len > NEWENV_SPACE / x) {
errno = ENOMEM;
return 0;
}
byte_copy(n.es + n.eslen, slen, s);
n.eslen += slen;
n.es[n.eslen++] = '=';
byte_copy(n.es + n.eslen, tlen, t);
n.eslen += tlen;
n.es[n.eslen++] = 0;
n.e[n.elen++] = n.es + n.eslen - len;
n.e[n.elen] = 0;
return 1;
}
/*
The 'newenv_copyenv' function copies the variable from current environment into
new environment.
*/
int newenv_copyenv(const char *s) {
char *t;
if (!s) bug_inval();
t = env_get(s);
if (!t) {
errno = ENOENT;
return 0;
}
return newenv_env_(1, s, t);
}
/*
The 'newenv_exec' function executes the command in new environment.
*/
void newenv_exec(char *filename, char **argv) {
if (!argv || !filename) bug_inval();
execve(filename, argv, n.e);
}
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