+#endif
+
+
+/* Hook execve() and the other exec*() functions. Some shells use exec*() with
+ * a custom environment which doesn't necessarily contain our updates to
+ * ENV_NAME_FDS. It's also faster to update the environment only when
+ * necessary, right before the exec() to pass it to the new process. */
+
+static int (*real_execve)(const char *filename, char *const argv[], char *const env[]);
+int execve(const char *filename, char *const argv[], char *const env[]) {
+ DLSYM_FUNCTION(real_execve, "execve");
+
+ int found = 0;
+ size_t index = 0;
+
+ /* Count arguments and search for existing ENV_NAME_FDS environment
+ * variable. */
+ size_t count = 0;
+ char * const *x = env;
+ while (*x) {
+ if (!strncmp(*x, ENV_NAME_FDS "=", strlen(ENV_NAME_FDS) + 1)) {
+ found = 1;
+ index = count;
+ }
+
+ x++;
+ count++;
+ }
+ /* Terminating NULL. */
+ count++;
+
+ char *env_copy[count + 1 /* space for our new entry if necessary */];
+ memcpy(env_copy, env, count * sizeof(char *));
+
+ /* Make sure the information from the environment is loaded. We can't just
+ * do nothing (like update_environment()) because the caller might pass a
+ * different environment which doesn't include any of our settings. */
+ if (!initialized) {
+ init_from_environment();
+ }
+
+ char fds_env[strlen(ENV_NAME_FDS) + 1 + update_environment_buffer_size()];
+ strcpy(fds_env, ENV_NAME_FDS "=");
+ update_environment_buffer(fds_env + strlen(ENV_NAME_FDS) + 1);
+
+ if (found) {
+ env_copy[index] = fds_env;
+ } else {
+ /* If the process removed ENV_NAME_FDS from the environment, re-add
+ * it. */
+ env_copy[count-1] = fds_env;
+ env_copy[count] = NULL;
+ }
+
+ return real_execve(filename, argv, env_copy);
+}
+
+#define EXECL_COPY_VARARGS_START(args) \
+ va_list ap; \
+ char *x; \
+ \
+ /* Count arguments. */ \
+ size_t count = 1; /* arg */ \
+ va_start(ap, arg); \
+ while (va_arg(ap, const char *)) { \
+ count++; \
+ } \
+ va_end(ap); \
+ \
+ /* Copy varargs. */ \
+ char *args[count + 1 /* terminating NULL */]; \
+ args[0] = (char *)arg; \
+ \
+ size_t i = 1; \
+ va_start(ap, arg); \
+ while ((x = va_arg(ap, char *))) { \
+ args[i++] = x; \
+ } \
+ args[i] = NULL;
+#define EXECL_COPY_VARARGS_END(args) \
+ va_end(ap);
+#define EXECL_COPY_VARARGS(args) \
+ EXECL_COPY_VARARGS_START(args); \
+ EXECL_COPY_VARARGS_END(args);
+
+int execl(const char *path, const char *arg, ...) {
+ EXECL_COPY_VARARGS(args);
+
+ update_environment();
+ return execv(path, args);
+}
+
+int execlp(const char *file, const char *arg, ...) {
+ EXECL_COPY_VARARGS(args);
+
+ update_environment();
+ return execvp(file, args);
+}
+
+int execle(const char *path, const char *arg, ... /*, char *const envp[] */) {
+ EXECL_COPY_VARARGS_START(args);
+ /* Get envp[] located after arguments. */
+ char * const *envp = va_arg(ap, char * const *);
+ EXECL_COPY_VARARGS_END(args);
+
+ return execve(path, args, envp);
+}
+
+static int (*real_execv)(const char *path, char *const argv[]);
+int execv(const char *path, char *const argv[]) {
+ DLSYM_FUNCTION(real_execv, "execv");
+
+ update_environment();
+ return real_execv(path, argv);
+}
+
+static int (*real_execvp)(const char *path, char *const argv[]);
+int execvp(const char *path, char *const argv[]) {
+ DLSYM_FUNCTION(real_execvp, "execvp");
+
+ update_environment();
+ return real_execvp(path, argv);
+}