/* return codes: -1 is error; 0 is everything OK but did not find shebang;
if shebang is found, does an exec */
static int attempt_shebang_launch(char *program_to_launch, char *origin, char *profile_bin_dir,
int argc, char **argv) {
/* Attempt to open the file to scan for a shebang, which we handle
ourself. (If a script is executable but not readable then no
interpreter can read it anyway; assume such a thing doesn't
exist.) */
FILE *f;
char shebang[SHEBANG_MAX], interpreter[SHEBANG_MAX], arg[SHEBANG_MAX];
char *r, *s, *interpreter_part, *arg_part = NULL;
char **new_argv;
char **p;
/* read first line */
if ((f = fopen(program_to_launch, "r")) == NULL) return -1;
r = fgets(shebang, SHEBANG_MAX, f);
fclose(f);
if (r == NULL) return -1;
/* Reference: http://homepages.cwi.nl/~aeb/std/hashexclam.html */
/* TODO: There's a Mac OS X special case on interpreter handling.. */
/* shebang header */
if (r[0] != '#' || r[1] != '!') return 0; /* shebang not present return code */
r += 2;
skip_whites(&r);
if (r == '\0') return -1;
interpreter_part = r;
skip_nonwhites(&r);
if (*r != '\0') {
*r = '\0'; /* terminate 'interpreter' string */
++r;
skip_whites(&r);
/* there may be an argument: */
arg_part = r;
rstrip(arg_part);
}
if (expandvars(interpreter, interpreter_part, origin, profile_bin_dir, SHEBANG_MAX) != 0) return -1;
if (arg_part != NULL) {
if (expandvars(arg, arg_part, origin, profile_bin_dir, SHEBANG_MAX) != 0) return -1;
} else {
arg[0] = '\0';
}
if (debug) {
fprintf(stderr, "%sshebang_cmd=%s\n", debug_header, interpreter);
fprintf(stderr, "%sshebang_arg=%s\n", debug_header, arg);
}
/* Done parsing, do launch */
new_argv = malloc(sizeof(char*) * (argc + 3));
p = new_argv;
p++; /* we'll set interpreter below */
if (arg[0]) *p++ = arg;
/* substitute argv[0] with program_to_launch */
argv++;
*p++ = program_to_launch;
while (*argv) *p++ = *argv++;
*p = NULL;
/* The interpreter string may contain : to separate many possible interpreters;
try them in turn. */
s = interpreter;
for (;;) {
r = strstr(s, ":");
if (r != NULL) r[0] = '\0';
new_argv[0] = s;
execv(s, new_argv);
if (r == NULL) break;
s = r + 1;
}
/* failed to execute */
free(new_argv);
return -1;
}
std::string path::expand(const std::string &path) {
return normpath(expandvars(expanduser(path)));
}
