CITS2002 Systems Programming  
← prev
next → CITS2002 CITS2002 schedule  

Investigating the contents of a directory

We now know how to open a directory for reading, and to determine the names of all items in that directory.

What is each "thing" found in the directory - is it a directory, is it a file...?

To answer those questions, we need to employ the POSIX function, stat(), to determine the attributes of the items we find in directories: 

#include  <stdio.h>
#include  <sys/types.h>
#include  <sys/stat.h>
#include  <sys/param.h>
#include  <dirent.h>
#include  <unistd.h>

void list_directory(char *dirname)
{
    char  fullpath[MAXPATHLEN];

    .....
    while((dp = readdir(dirp)) != NULL) {
        struct stat  stat_buffer;


        sprintf(fullpath, "%s/%s", dirname, dp->d_name );

        if(stat(fullpath, &stat_buffer) != 0) {
             perror( progname );
        }
        else if( S_ISDIR( stat_buffer.st_mode )) {
            printf( "%s is a directory\n", fullpath );
        }
        else if( S_ISREG( stat_buffer.st_mode )) {
            printf( "%s is a regular file\n", fullpath );
        }
        else {
            printf( "%s is unknown!\n", fullpath );
        }
    }
    closedir(dirp);
}

#include  <stdio.h>
#include  <sys/types.h>
#include  <sys/stat.h>
#include  <sys/param.h>
#include  <dirent.h>
#include  <unistd.h>

void list_directory(char *dirname)
{
    char  fullpath[MAXPATHLEN];

    .....
    while((dp = readdir(dirp)) != NULL) {
        struct stat  stat_buffer;
        struct stat  *pointer = &stat_buffer;

        sprintf(fullpath, "%s/%s", dirname, dp->d_name );

        if(stat(fullpath, pointer) != 0) {
             perror( progname );
        }
        else if( S_ISDIR( pointer->st_mode )) {
            printf( "%s is a directory\n", fullpath );
        }
        else if( S_ISREG( pointer->st_mode )) {
            printf( "%s is a regular file\n", fullpath );
        }
        else {
            printf( "%s is unknown!\n", fullpath );
        }
    }
    closedir(dirp);
}

 

CITS2002 Systems Programming, Lecture 16, p7, 19th September 2023.