ast_comparator/test/student_data/handout/shlab-handout/cases/reference_2_tsh.c
/* 
 * builtin_cmd - If the user has typed a built-in command then execute
 *    it immediately.  
 */
If the user has typed a built-in command then execute
it immediately.
If the user has typed a built - in command then execute it immediately .
int builtin_cmd(char **argv) 
{
    if (!strcmp(argv[0], "quit")) {
        exit(0);
    } 
    else if (!strcmp("jobs", argv[0])) {  
        listjobs(jobs);  
        return 1;  
    }  
    else if (!strcmp("bg", argv[0]) || !(strcmp("fg", argv[0]))) {  
        do_bgfg(argv);  
        return 1;  
    }
    else if (!strcmp("&", argv[0])){
        return 1;
    }
    return 0;   
}
int builtin_cmd ( char * * argv ) { if ( ! strcmp ( argv [ 0 ] , " " ) ) { exit ( 0 ) ; } else if ( ! strcmp ( " " , argv [ 0 ] ) ) { listjobs ( jobs ) ; return 1 ; } else if ( ! strcmp ( " " , argv [ 0 ] ) || ! ( strcmp ( " " , argv [ 0 ] ) ) ) { do_bgfg ( argv ) ; return 1 ; } else if ( ! strcmp ( " " , argv [ 0 ] ) ) { return 1 ; } return 0 ; }
builtin_cmd - If the user has typed a built-in command then execute
    it immediately.
builtin_cmd - If the user has typed a built - in command then execute it immediately .
// see if this is a built in command, ignores command if & is the first char /* not a builtin command */