CODEWITHSUNDEEP
csizebytelong-integerstat
Rob
Rob

Reputation: 3

C - Recursive call to traverse sub-directory and print all files + sizes (using stat)

I have a program that recursively prints the cwd size plus containing file sizes and repeats for each sub directory.

Recursive directory traversal function: (Note the reason for printf in this function and passing two strings is that the output needs to be in a special format so I can't just output the actual filepath. Also I am just learning about system calls to work with directories in ubuntu so if you have any comments on improvements on the code I would appreciate them (style or using something more simple to accomplish the same).

#include <sys/stat.h>
#include <limits.h>
#include <dirent.h>
#include <libgen.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define TRUE 1 
#define FALSE 0
#define FIRST_ARG 1
#define SECOND_ARG 2
char* fileName;
FILE* fileToRead;
DIR* directoryToRead;
int printFileSize(char*);
int printWorkingSize(char*, char*);
int printSize(char*, char*);
int printDir(char*, char*);
int printCurrentDir(char*, char*);
int bytesToKbytes(long long, char*);
int main(int argc, char** argv) {
    if(argc == FIRST_ARG) {
        char currentDir[PATH_MAX + 1] = "";
        char* currentDirectory;
        directoryToRead = opendir (".");
        if (directoryToRead == NULL){
            exit (EXIT_FAILURE);
        }
        closedir(directoryToRead);
        printCurrentDir(currentDirectory, ".");
    }
return 0;
}

int printCurrentDir(char* name, char* path) {
    struct dirent *dir;
    struct stat statBuffer;
    char fileName[PATH_MAX + 1];
    char filePath[PATH_MAX + 1];
    DIR* openDir;
    if((openDir = opendir(path)) == NULL) {
        printf("Could not open %s\n", path);
    }    
    stat(path, &statBuffer);
    if(strcmp(path, ".") == 0) {
        printf("%lld .\n", (long long)statBuffer.st_size);
    }   else {
            printf("%lld %s\n", (long long)statBuffer.st_size, name);
    }
    while (TRUE) {  // go through contents of current directory
        dir = readdir(openDir);
        if(!dir) {
            break;
        }
        if((strcmp(dir->d_name, "..") == 0) || (strcmp(dir->d_name,".") == 0)) {
            continue;
        }
        if(name == NULL) {
            strcpy(fileName, dir->d_name);
        } else {
        strcpy(fileName, name);
        strcat(fileName, "/");
        strcat(fileName, dir->d_name);
        }
        strcpy(filePath, path);
        strcat(filePath, "/");
        strcat(filePath, dir->d_name);
        if(dir->d_type == DT_DIR) {  // if the next file is a directory
            if(!printCurrentDir(fileName, filePath)) {
                return FALSE;
            }
        } 
        else if(!printWorkingSize(fileName, filePath)) {
            return FALSE;
        }
    }
    return TRUE;
}

//output file size in bytes followed by name-> (char* file)
int printWorkingSize(char* file, char* path) {
    struct stat statBuffer;
    stat(path, &statBuffer);
    char result[PATH_MAX];
    if(bytesToKbytes((long long)statBuffer.st_size, result) == FALSE) {
        sprintf(result, "%lld", (long long)statBuffer.st_size);
    }
    printf("%5s %s\n", result, path);
    return TRUE;
        }


// convert bytes to kilobytes if more than 5 digits
int bytesToKbytes(long long bytes, char* result) {
    if(!(bytes > 99999)) {
        return FALSE;
    }
    char size[PATH_MAX];
    sprintf(size, "%lld", bytes);
    size[3] = 'K';
    size[4] = '\0';
    strcpy(result, size);
    return TRUE;
}

Upvotes: 0

Views: 4759

Answers (2)

Basile Starynkevitch
Basile Starynkevitch

Reputation: 1

It is operating system specific. On Linux and POSIX, you should simply use the nftw(3) library function, which is recursively reading the directories and already calling stat(2) for you.

Upvotes: 1

Serge Ballesta
Serge Ballesta

Reputation: 148910

The problem is effectively in the way you use bytesToKbytes. It returns a boolean to indicate if it wrote anything in result and :

  • you do not preload anything in result before calling bytesToKbytes
  • you do not test return value to write anything in resul if size was less than 99999

You could use : 

int printWorkingSize(char* file, char* path) {
    struct stat statBuffer;
    stat(path, &statBuffer);
    char result[PATH_MAX];
    if (! bytesToKbytes((long long)statBuffer.st_size, result)) {
        sprintf(result, "%lld", (long long)statBuffer.st_size);
    }
    printf("%5s %s\n", result, path);
    return TRUE;
}

You could also change bytesToKbytes to put length in bytes into resul if size is less than 99999

Upvotes: 0

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