ece282/lab04/ls3.c

/* ls3.c
 *	purpose  list contents of directory or directories
 *	action   if no args, use .  else list files in args
 *	note     uses stat and pwd.h and grp.h 
 *	BUG: try ls3 /tmp  
 */
#include	<stdio.h>
#include	<sys/types.h>
#include	<dirent.h>
#include	<sys/stat.h>
#include	<string.h>
#include	<stdlib.h>

#include	"mode_to_letters.h"
#include	"gid_to_name.h"
#include	"show_file_info.h"
#include	"uid_to_name.h"

void do_ls(char[]);
void dostat(char *, char *);

int main(int ac, char *av[])
{
	if ( ac == 1 )
		do_ls( "." );
	else
		while ( --ac ){
			printf("%s:\n", *++av );
			do_ls( *av );
		}
}

void do_ls( char dirname[] )
/*
 * List files in directory called dirname
 */
{
    DIR *dir_ptr;         // Directory pointer
    struct dirent *direntp;  // Each entry in directory

    if ( (dir_ptr = opendir(dirname)) == NULL )   // Open directory
    {
        fprintf(stderr, "ls3: cannot open %s\n", dirname);
    }
    else
    {
        // Read each entry in the directory
        while ( (direntp = readdir(dir_ptr)) != NULL )
        {
            // Skip . and .. directories
            if ( strcmp(direntp->d_name, ".") == 0 || strcmp(direntp->d_name, "..") == 0 )
                continue;

            // Construct the full path
            char *full_path = (char *)malloc(strlen(dirname) + strlen(direntp->d_name) + 2);  // +2 for '/' and '\0'
            if (!full_path) {
                fprintf(stderr, "Memory allocation error\n");
                closedir(dir_ptr);
                return;
            }

            // Concatenate the directory path and file name
            if (dirname[strlen(dirname) - 1] == '/')  // If dirname ends with '/', just concatenate
                sprintf(full_path, "%s%s", dirname, direntp->d_name);
            else  // If dirname doesn't end with '/', add a '/'
                sprintf(full_path, "%s/%s", dirname, direntp->d_name);

            // Call dostat to display file info
            dostat(full_path, direntp->d_name);

            // Free the allocated memory for full_path
            free(full_path);
        }
        closedir(dir_ptr);
    }
}

void dostat( char *full_path, char *filename )
{
    struct stat info;

    if ( stat(full_path, &info) == -1 )  // Cannot stat file
        perror(filename);  // Show error
    else  // Show file info
        show_file_info(filename, &info);
}