On Wed, Oct 22, 2008 at 11:01 PM, Raz <raziebe@xxxxxxxxx> wrote: > no. > I mean i want to remove a portion of the file : > if a file is composed of : a,b,c,d blocks. > I want to be able to remove from the **disk** block c or block a. > ftruncate remove the end. Hmmm. I don't know if there is a simple way.........but you can do it with a simple C program. Let say you have blocks a,b,c,d and you want to create holes at blocks b,c. Code flow would be something like this. Open source file : src read 'blocksize' chars and put it in dest lseek both src and dest 2*blocksize read block d and copy it to dest rename dest to src. The other option that you have is to directly modify the filesystem reading it as a block device. Unfortunately I only know a bit about ext filesystems :-( . In that case you will have to perform below steps. a) Go and set the appropriate block pointer in inode as 0 at appropriate offset. b) Go and mark the corresponding bit for that block as 1. c) Update the superblock for the blocks used count and other stats in block group descriptors. And again things are not simple if this is ext4 :-). Thanks - Manish > > On Wed, Oct 22, 2008 at 7:24 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote: >> On Wed, Oct 22, 2008 at 10:42 PM, Raz <raziebe@xxxxxxxxx> wrote: >>> or a file system that can do it ? >> >> What does that mean ??? >> >> just doing >> >> $ > filename >> on command line will truncate it............or probably "man >> ftruncate" can help you. >> >> Thanks - >> Manish >> >> >>> >>> thank you >>> raz >>> >>> -- >>> To unsubscribe from this list: send an email with >>> "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx >>> Please read the FAQ at http://kernelnewbies.org/FAQ >>> >>> >> > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
