Append to the end of a file in C

Question

I m trying to append the contents of a file myfile txt to the end of a second file myfile2 txt in c  I can copy the contents  but I can t find a way to append  Here s my code   FILE  pFile  FILE  pFile2  char buffer 256    pFile fopen  myfile txt    r    pFile2 fopen  myfile2 txt   r    if pFile  NULL        perror  Error opening file       else       while  feof pFile             if fgets buffer  100  pFile     NULL            fseek pFile2  -100  SEEK END           fprintf pFile2  buffer           fclose pFile   fclose pFile2     I don t think I m using fseek correctly  but what I m trying to do is call fseek to put the pointer at the end of the file  then write at the location of that pointer  instead of at the beginning of the file  Is this the right approach

User · Accepted Answer

Open with append   pFile2   fopen  myfile2 txt    a      then just write to pFile2  no need to fseek

User · Answer

Following the documentation of fopen        a     Open for writing   The file is created if it does not exist   The stream is positioned at                the end of the file   Subsequent writes to the file will always end up at the then cur-                rent end of file  irrespective of any intervening fseek 3  or similar    So if you pFile2 fopen  myfile2 txt    a    the stream is positioned at the end to append automatically  just do   FILE  pFile  FILE  pFile2  char buffer 256    pFile fopen  myfile txt    r    pFile2 fopen  myfile2 txt    a    if pFile  NULL        perror  Error opening file       else       while fgets buffer  sizeof buffer   pFile             fprintf pFile2    s   buffer           fclose pFile   fclose pFile2

[c] Append to the end of a file in C

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