如何解决按字母顺序排列的问题？

Question

Well actually im trying to replicate ls function with -la switches and i kinda got it, but there i got a huge problem, because i learned about dirent.h recently and have no idea how to get alphabetical order by file name, also formatting is bad because i want to have it "column under column". I thought about arrays, but cant imagine how it should be done. This is the code:

#include <stdio.h>
#include <stdlib.h>

#include <sys/stat.h>
#include <sys/types.h>

#include <dirent.h>
#include <unistd.h>

#include <grp.h>
#include <pwd.h>
#include <time.h>

void list_dir(char *name) {
DIR *dir;
struct dirent *dp;
struct stat statbuf;

struct group *grp;
struct passwd *pwd;

char *t;
int i;

if ((dir = opendir(name)) == NULL) {
    perror("Error");
}
while ((dp = readdir(dir)) != NULL) {
    if (stat(dp->d_name, &statbuf) == -1)
        continue;

    switch (statbuf.st_mode & S_IFMT){
    case S_IFBLK:  printf("b"); break;
        case S_IFCHR:  printf("c"); break; 
        case S_IFDIR:  printf("d"); break; 
        case S_IFIFO:  printf("p"); break; 
        case S_IFLNK:  printf("l"); break;
        case S_IFSOCK: printf("s"); break;
    default:       printf("-"); break;
} 
    printf( (statbuf.st_mode & S_IRUSR) ? "r" : "-");
printf( (statbuf.st_mode & S_IWUSR) ? "w" : "-");
printf( (statbuf.st_mode & S_IXUSR) ? "x" : "-");
printf( (statbuf.st_mode & S_IRGRP) ? "r" : "-");
printf( (statbuf.st_mode & S_IWGRP) ? "w" : "-");
printf( (statbuf.st_mode & S_IXGRP) ? "x" : "-");
printf( (statbuf.st_mode & S_IROTH) ? "r" : "-");
printf( (statbuf.st_mode & S_IWOTH) ? "w" : "-");
printf( (statbuf.st_mode & S_IXOTH) ? "x" : "-");

printf(" %zu",statbuf.st_nlink);
  

    if((pwd = getpwuid(statbuf.st_uid)) != NULL)
        printf(" %s", pwd->pw_name);
    else
        printf(" %d", statbuf.st_uid);


    if((grp = getgrgid(statbuf.st_gid)) != NULL)
        printf(" %s", grp->gr_name);
    else
        printf(" %d", statbuf.st_gid);

printf(" %zu ", statbuf.st_size);
t=ctime(&statbuf.st_mtime);
for(i=4;i<=15;i++)
    printf("%c",t[i]);

    printf(" %s\n", dp->d_name);

}
closedir(dir);

}

int main(int argc, char **argv) {
list_dir(".");
exit(0);
}

So anyone have any idea how to do this?

Answer 1

Implement localization via #include <locale.h> , and adding setlocale(LC_COLLATE, ""); (affecting only string collation/sorting) or setlocale(LC_ALL, ""); near the beginning of your main() .

Then, use glob() ( man 3 glob ) without the GLOB_NOSORT flag, or scandir() ( man 3 scandir ) with alphasort as the comparison function, and you'll get correctly sorted file names according to your current locale.