get_location.c

/* works just like the which command */
#include "main.h"

/**
 * get_location - finds the location of a given command in the system's PATH
 * @command: the command to locate
 *
 * Return: a string containing the full path to the command, or NULL if not found
*/

char *get_location(char *command)
{
    char *path, *path_copy, *path_token, *file_path;
    int command_len, directory_len;
    struct stat buffer;

    path = getenv("PATH");

    if (path)
    {
        /* Duplicate the path string - free up memory for strdup() */
        path_copy = strdup(path);
        /* Get the length of the command that was passed */
        command_len = strlen(command);

        /* Break down the path into individual tokens to get all the directories available */
        path_token = strtok(path_copy, ":");

        while (path_token != NULL)
        {
            /* get the length of the directory */
            directory_len = strlen(path_token);
            /* allocate memory for storing the command name and directory name */
            file_path = malloc(command_len + directory_len + 2);
            /* to build the path for the command, let's copy the directory path and concatenate the command to it */
            strcpy(file_path, path_token);
            strcat(file_path, "/");
            strcat(file_path, command);
            strcat(file_path, "\0");

            /* test if this file path actually exists and return it if it does, otherwise try the next directory */
            if (stat(file_path, &buffer) == 0)
            {
                /* return 0 if file_path is valid */
                free(path_copy);
                
                return (file_path);
            }
            else
            {
                /* free file_path memory so we can check another path */
                free(file_path);
                path_token = strtok(NULL, ":");
            }
        }

        /* if file_path doesn't exist return NULL, but free path_copy */
        free(path_copy);

        /* see if the command itself is a file_path that exists */
        if (stat(command, &buffer) == 0)
        {
            return (command);
        }

        return (NULL);
    }

    return (NULL);
}