am a3f89eab: add a run_program() function to edify

#include <sys/mount.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <unistd.h>

#include "cutils/misc.h"

    return buffer;

}

char* RunProgramFn(const char* name, State* state, int argc, Expr* argv[]) {

    if (argc < 1) {

        return ErrorAbort(state, "%s() expects at least 1 arg", name);

    }

    char** args = ReadVarArgs(state, argc, argv);

    if (args == NULL) {

        return NULL;

    }

    char** args2 = malloc(sizeof(char*) * (argc+1));

    memcpy(args2, args, sizeof(char*) * argc);

    args2[argc] = NULL;

    fprintf(stderr, "about to run program [%s] with %d args\n", args2[0], argc);

    pid_t child = fork();

    if (child == 0) {

        execv(args2[0], args2);

        fprintf(stderr, "run_program: execv failed: %s\n", strerror(errno));

        _exit(1);

    }

    int status;

    waitpid(child, &status, 0);

    if (WIFEXITED(status)) {

        if (WEXITSTATUS(status) != 0) {

            fprintf(stderr, "run_program: child exited with status %d\n",

                    WEXITSTATUS(status));

        }

    } else if (WIFSIGNALED(status)) {

        fprintf(stderr, "run_program: child terminated by signal %d\n",

                WTERMSIG(status));

    }

    int i;

    for (i = 0; i < argc; ++i) {

        free(args[i]);

    }

    free(args);

    free(args2);

    char buffer[20];

    sprintf(buffer, "%d", status);

    return strdup(buffer);

}

void RegisterInstallFunctions() {

    RegisterFunction("mount", MountFn);

    RegisterFunction("apply_patch_space", ApplyPatchFn);

    RegisterFunction("ui_print", UIPrintFn);

    RegisterFunction("run_program", RunProgramFn);

}