env.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "Command.h"

void expand_variables(void) {
    int i, j;
    for (i = 0; i < num_commands; i++) {
        for (j = 0; j < commands[i].argc; j++) {
            if (commands[i].args[j][0] == '$') {
                char *var_name = commands[i].args[j] + 1;
                char *var_value = getenv(var_name);
                free(commands[i].args[j]);
                commands[i].args[j] = strdup(var_value ? var_value : "");
            }
        }
        if (commands[i].input_file && commands[i].input_file[0] == '$') {
            char *var_name = commands[i].input_file + 1;
            char *var_value = getenv(var_name);
            free(commands[i].input_file);
            commands[i].input_file = strdup(var_value ? var_value : "");
        }
        if (commands[i].output_file && commands[i].output_file[0] == '$') {
            char *var_name = commands[i].output_file + 1;
            char *var_value = getenv(var_name);
            free(commands[i].output_file);
            commands[i].output_file = strdup(var_value ? var_value : "");
        }
    }
}