id3tag.c

#include <stdio.h>
#include <id3v2lib.h>
#include <dirent.h>
#include <string.h> 
#include <stdlib.h>
#include <unistd.h>
#include "id3tag.h"

static int one(){
  //Allow everything through by directly returning 1
	return 1;
}

int checkSuffix(const char *str, const char *suffix){
  // Check file extention
  if (!str || !suffix){
    return -1;
  }
  size_t lenstr = strlen(str);
  size_t lensuffix = strlen(suffix);
  if (lensuffix > lenstr){
    return -1;
  }
  return strcmp(str + (lenstr - lensuffix), suffix);
}

char* returnExt(const char *str){
  // Returns the file extention
  char* ext = strrchr(str,'.');
  return ext;
}

int prepareName(ID3v2_Tag *tag, char* newName){
  // Prepend track number to the beginning of the file name
  ID3v2_TextFrame* track_frame = ID3v2_Tag_get_track_frame(tag);
  ID3v2_TextFrame* title_frame = ID3v2_Tag_get_title_frame(tag);
  for(int i = 0; i < strlen(track_frame->data->text); i++){
    if(track_frame->data->text[i] == '/'){
      newName[i] = '\0';
      break;
    }
    newName[i] = track_frame->data->text[i];
  }
  strcat(newName," - ");
  strcat(newName,title_frame->data->text);
  return 0;
}

int readDir(char* dir){
  // Read directory and prepend all track numbers to mp3 file names
  const char* ext = ".mp3";
  struct dirent **eps;
  int n = scandir(dir, &eps, one, alphasort);
  if(n >= 0){
    for(int i = 0; i < n; i++){
      if(checkSuffix(eps[i]->d_name,ext) == 0){
	renameFile(eps[i]->d_name);
      }
    }
  }
}

int renameFile(char *fPath){
  // Rename the file using the prepareName()
  ID3v2_Tag* tag = ID3v2_read_tag(fPath);
  if(tag == NULL){
    printf("File does not have a tag\n");
    return -1;
  }
  char newName[PATH_MAX];
  if(prepareName(tag, newName) != 0){
    printf("Error preparing name\n");
  }
  strcat(newName,returnExt(fPath));
  if(rename(fPath, newName) != 0){
    perror("Error");
  }
}

int printTag(char *fPath){
  ID3v2_Tag* tag = ID3v2_read_tag(fPath);
  if(tag == NULL){
    printf("File does not have a tag\n");
    return -1;
  }
  ID3v2_TextFrame* track_frame = ID3v2_Tag_get_track_frame(tag);
  ID3v2_TextFrame* title_frame = ID3v2_Tag_get_title_frame(tag);
  ID3v2_TextFrame* artist_frame = ID3v2_Tag_get_artist_frame(tag);
  ID3v2_TextFrame* album_frame = ID3v2_Tag_get_album_frame(tag);
  printf("Title: %s\n",title_frame->data->text);
  printf("Track: %s\n",track_frame->data->text);
  printf("Artist: %s\n",artist_frame->data->text);
  printf("Album: %s\n",album_frame->data->text);
}


int main(int argc, char *argv[]){

  if(argc<2){
    printf("Options:\n");
    printf("p: Prints file tag\n");
    printf("r: Adds track number to the file name\n");
    printf("r: Adds track number to all mp3 files in directory\n");
    return -1;
  }
  int opt;
  while((opt = getopt(argc, argv, "p:r:d:")) != -1)
    {
      switch(opt){
      case 'r':
	renameFile(optarg);
	break;
      case 'p':
	printTag(optarg);
	break;
      case 'd':
	readDir(optarg);
	break;
      case ':':
	printf("option needs a value\n");
	break;
      case '?':
	printf("unknown option: %c\n", optopt);
	break;
      }
    }
  for(; optind < argc; optind++){
    printf("extra arguments: %s\n", argv[optind]);
  }
  return 0;
}