proc_run.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
#define popen _popen
#define pclose _pclose
#endif

case OP_PROC_RUN: {
 /* Pops command string; pushes map {"out": string, "code": int} */
 Value cmdv = pop_value(vm);
 char *cmd = value_to_string_alloc(&cmdv);
 free_value(cmdv);
 if (!cmd) {
 Value m = make_map_empty();
 map_set(&m, "out", make_string(""));
 map_set(&m, "code", make_int(-1));
 push_value(vm, m);
 break;
 }

 /* Use popen to run via shell and capture stdout */
 FILE *fp = popen(cmd, "r");
 int exit_code = -1;
 char *out = NULL;
 size_t cap = 0, len = 0;
 if (fp) {
 cap = 4096;
 out = (char *)malloc(cap);
 if (!out) {
 pclose(fp);
 free(cmd);
 Value m = make_map_empty();
 map_set(&m, "out", make_string(""));
 map_set(&m, "code", make_int(-1));
 push_value(vm, m);
 break;
 }
 int c;
 while ((c = fgetc(fp)) != EOF) {
 if (len + 1 >= cap) {
 cap *= 2;
 char *nb = (char *)realloc(out, cap);
 if (!nb) {
 free(out);
 pclose(fp);
 free(cmd);
 Value m = make_map_empty();
 map_set(&m, "out", make_string(""));
 map_set(&m, "code", make_int(-1));
 push_value(vm, m);
 goto done_push;
 }
 out = nb;
 }
 out[len++] = (char)c;
 }
 out[len] = '\0';
 int status = pclose(fp);
#ifdef __unix__
 if (WIFEXITED(status))
 exit_code = WEXITSTATUS(status);
 else
 exit_code = -1;
#else
 exit_code = status;
#endif
 } else {
 out = strdup("");
 exit_code = -1;
 }

 Value m = make_map_empty();
 map_set(&m, "out", make_string(out ? out : ""));
 map_set(&m, "code", make_int(exit_code));
 push_value(vm, m);

done_push:
 if (out) free(out);
 free(cmd);
 break;
}