ls1.c

unix linux 编程实践源代码

/** ls1.c
 **   purpose  list contents of directory or directories
 **   action   if no args, use .  else list files in args
 **/
#include	<stdio.h>
#include	<sys/types.h>
#include	<dirent.h>

void do_ls(char []);

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;		/* the directory */
	struct dirent	*direntp;		/* each entry	 */

	if ( ( dir_ptr = opendir( dirname ) ) == NULL )
		fprintf(stderr,"ls1: cannot open %s\n", dirname);
	else
	{
		while ( ( direntp = readdir( dir_ptr ) ) != NULL )
			printf("%s\n", direntp->d_name );
		closedir(dir_ptr);
	}
}