Deleting a line from a file

[Saket Sinha]

Please find my response inline-

On Wed, May 14, 2014 at 8:04 PM, Bernd Petrovitsch
<bernd at petrovitsch.priv.at> wrote:
> Hi!
>
> The original mail is off-topic as it has nothing to do wotj the Linux
> kernel development as such, but:
>

I wanted to isolate the problem hence did not give the full context.
Actually I have written a file-system utility which mounts my
filesystem on a specific path and update it in /etc/fstab. When I
umount it, I delete the path from the /etc/fstab.


I had earlier written a C function to do that  but it is corrupting the fstab.
 SO now I am trying to run the above sed command this way
 system(sed -i 's#^/opt/new1.*$##g' /etc/fstab).


The C function that was currupting the filesystem is listed below -


int removeEntryFromFSTAB(const char * fullPath, const char * fileName)
{
     FILE *tabFileOld = NULL;
     FILE *tabFileNew = NULL;
     struct mntent *m;
     char newFileName[PATH_MAX];
     int rc = -1;

     tabFileOld = setmntent( fileName, "r" ); // Open for writing now
     if (tabFileOld == NULL )
           goto end;

     tabFileNew = setmntent(newFileName, "w");
     if (tabFileNew == NULL )
           goto end;

     while ((m = getmntent(tabFileOld)) != NULL)
     {
          if (tcscmp(MY_FS_TYPE, m->mnt_type) == 0)
          {
              if ((tcscmp(fullPath, m->mnt_dir) == 0))
                             continue;
          }
          if (addmntent(tabFileNew, m) != 0)
               goto end;
     }
     endmntent(tabFileOld);
     endmntent(tabFileNew);

     tabFileNew = NULL;
     tabFileOld = NULL;


     rename(newFileName, fileName))
     rc = 0;

     end:
      if (tabFileNew != NULL)
          endmntent(tabFileNew);

      if (tabFileOld != NULL)
          endmntent(tabFileOld);

      sync();
      return rc;
  }

Kindly let me know, if you think there is a better way.

Regards,
Saket Sinha