Question

11. Given: struct stat myst.myst.st_mode, myst.st atime Write C code to get information of a filename: Write C code to determine whether filename is a REGular file or a DIRectory Write C code to test whether the file is writeable by others: Readable by Others: Write C code to print the file's access time in CALENDAR form

Answer 1

Please find all 4 C code below:

//C code to determine whether filename is a Regular file or a Directory.

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

void printType(mode_t iMode);

int main(void){

    char *caArray[] = {"dir", "/run/avahi-daemon/socket", "test.txt", "/dev/sda", "/dev/tty0"};
    struct stat SBuffer;

    for(int i = 0; i < 5; i++){
        stat(caArray[i], &SBuffer);
        printf("File Name: %s\t", caArray[i]);
        printf("Inode: %lu\t", SBuffer.st_ino);
        printf("Type: ");
        printType(SBuffer.st_mode);
        printf("\n");
    }
    return 0;
}
void printType(mode_t iMode){
    if(S_ISREG(iMode)){
        printf("regular file");
        return;
    }
    if(S_ISDIR(iMode)){
        printf("directory");
        return;
    }
}

//C code to test whether the file is readable or writeable by others.

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

void listDir(char *name, FILE *fp)
{

    DIR *dir;
    struct dirent *entry;

    if (!(dir = opendir(name)))
        return;

    if (!(entry = readdir(dir)))
        return;

    do
    {
        char readString[50]  = {0};
        char writeString[50] = {0};
        char path[1024];
        char filetype;

        snprintf(path, sizeof(path)-1, "%s/%s", name, entry->d_name);

        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
            continue;

        if (access(path, R_OK) == 0)
            strcpy(readString, "Readable");
        else
            strcpy(readString, "Not Readable");

        if (access(path, W_OK) == 0)
            strcpy(writeString, "Writable");
        else
            strcpy(writeString, "Not Writable");

        switch (entry->d_type)
        {
            case  DT_UNKNOWN: filetype = '?'; break;
            case  DT_FIFO:    filetype = 'P'; break;
            case  DT_CHR:     filetype = 'C'; break;
            case  DT_DIR:     filetype = 'D'; break;
            case  DT_BLK:     filetype = 'B'; break;
            case  DT_REG:     filetype = 'F'; break;
            case  DT_LNK:     filetype = 'L'; break;
            case  DT_SOCK:    filetype = 'S'; break;
            case  DT_WHT:     filetype = 'W'; break;
            default:          filetype = '?'; break;
        }

        fprintf(fp,"[%c]%s - %s,%s\n", filetype, path, readString, writeString);

        if (entry->d_type == DT_DIR)
           listDir(path, fp);

    } while ((entry = readdir(dir)));

    closedir(dir);
}

int main(void)
{
    FILE *fp;
      fp = fopen("/var/mobile/Applications/FileIOAccess.txt", "w");
    listDir("/var",fp);
    fclose(fp);
    return 0;
}

//C code to get information of a filename

#include <stdio.h>

#include <stdlib.h>

int main()

{

char ch, file_name[25];

FILE *fp;

printf("Enter name of a file you wish to see\n");

gets(file_name);

fp = fopen(file_name, "r"); // read mode

if (fp == NULL)

{

  perror("Error while opening the file.\n");

  exit(EXIT_FAILURE);

}

printf("The contents of %s file are:\n", file_name);

while((ch = fgetc(fp)) != EOF)

  printf("%c", ch);

fclose(fp);

return 0;

}

//C code to print the file's access time in Calendar form

#include <time.h>
#include <stdio.h>
#include <sys/stat.h>
#include <stdlib.h>

char* formatdate(char* str, time_t val)
{
        strftime(str, 36, "%d.%m.%Y %H:%M:%S", localtime(&val));
        return str;
}

int main()
{
    int errno;
    const char* filename;
    filename = "stat.c";

    errno = 0;
    struct stat *file_info = malloc(sizeof(struct stat));
    if (lstat(filename, file_info) != 0) {
            perror("Error");
            exit(1);
    }

    char date[36];
    printf("Access: %s\n", formatdate(date, file_info->st_atime));
    printf("Modify: %s\n", formatdate(date, file_info->st_mtime));
    printf("Change: %s\n", formatdate(date, file_info->st_ctime));
    free(file_info);
    return 0;
}