st_mode not returning expected values for S_IXXX comparison

I have a function that (ideally) would merely simulate a portion of the ls -l command. It is meant to return permissions for the file, and the name of the file. I don't really care about any other information. It also is not the cleanest, as I am stuck using the VIM editor, and it is significantly less user friendly than modern IDEs.

Code:

#include <unistd.h>  #include <stdio.h>  #include <stdlib.h>  #include <sys/types.h>  #include <sys/stat.h>  #include <dirent.h>  #include <fcntl.h>    void ls_l(){      DIR *dir;      struct dirent *file;      struct stat fileStat;            dir = opendir("./dir0");      lstat(".", &fileStat);        while (((file = readdir(dir)) != NULL)){              lstat(file->d_name, &fileStat);              //User permissions                      printf( (fileStat.st_mode & S_IRUSR) ? " r" : " -");            printf( (fileStat.st_mode & S_IWUSR) ? "w" : "-");                printf( (fileStat.st_mode & S_IXUSR) ? "x" : "-");              //Group permissions            printf( (fileStat.st_mode & S_IRGRP) ? "r" : "-");            printf( (fileStat.st_mode & S_IWGRP) ? "w" : "-");            printf( (fileStat.st_mode & S_IXGRP) ? "x" : "-");              //Other permissions            printf("\n");      }  }    void doStep(int stepNum){      chdir("~/cs3377/project2/dir0");      switch (stepNum){          case 1:              printf("Display files and permissions for ./dir0\n");                 ls_l();          break;                    case 2:              printf("Change permission for file6.txt to -rwxrwx---\n");              chmod("./file6.txt", S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP |                  S_IWGRP | S_IXGRP);          break;                    case 3:              printf("Remove file1.txt and file2.txt from directory dir1\n");          break;            case 4:              printf("Remove dir1 directory\n");          break;            case 5:              printf("Display files and permission for ./dir0\n");              ls_l();          break;      }  }    int main(){      for (int i = 1; i < 2; i++){          doStep(i);      }      return 0;  }  

I am only through the user and group permissions and I already have noticed a serious problem with the code. For whatever reason, the group permissions fail to change with each file, and thus do not return the correct values. I am only aware of this because because changing the permissions of a file and checking the return with ls -l gives me different values that that of my code.

I am aware that this isn't a complete program, as I am not finished with it, but it can compile and run on my school UNIX server, so it should suffice for any testing.

I would also like to not that case 2 never functioned before I noticed this error, so if you'd like to help with that as well I would appreciate it.

Edit: I use this to compile: ''' gcc task13prog.c -o task13prog '''

https://stackoverflow.com/questions/66937148/st-mode-not-returning-expected-values-for-s-ixxx-comparison April 04, 2021 at 08:56AM