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________________________________ From: Raz <[EMAIL PROTECTED]> To: Karl Tatgenhorst <[EMAIL PROTECTED]> Cc: Manish Katiyar <[EMAIL PROTECTED]>; kernelnewbies <[email protected]> Sent: Thursday, 23 October, 2008 1:14:18 AM Subject: Re: any one knows how to truncate a file from its begining ? I think XFS can do it . it has some un/reserve space ioctl. 3521 /* 3522 * XFS_IOC_RESVSP and XFS_IOC_UNRESVSP will reserve or unreserve 3523 * file space. 3524 * These calls do NOT zero the data space allocated to the file, 3525 * nor do they change the file size. 3526 * 3527 * XFS_IOC_ALLOCSP and XFS_IOC_FREESP will allocate and free file 3528 * space. 3529 * These calls cause the new file data to be zeroed and the file 3530 * size to be changed. 3531 */ <kanishk> unreserve/reserve do not allocate/deallocate the blocks to the file where as the rest 2 do .... + These do not affect the file size....... thankx kanishk On Wed, Oct 22, 2008 at 8:07 PM, Karl Tatgenhorst <[EMAIL PROTECTED]> wrote: > if it is a binary file, use dd and figure out the offset to start from > (man dd will help). If it is a text file just use some perl like this: > > > > #open your file here > > $count=0; > $start_removing= 100; ###starting at 100 > $stop_removing= 300; ###end of block to remove > while<FILE> { > $count++; > if(100 < $count < 300) { > next; > } > print $_ > } > > both methods create a copy of the file and you can just copy your file over > it. > > good luck > > > On Wed, Oct 22, 2008 at 12:31 PM, Raz <[EMAIL PROTECTED]> 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. >> >> On Wed, Oct 22, 2008 at 7:24 PM, Manish Katiyar <[EMAIL PROTECTED]> wrote: >>> On Wed, Oct 22, 2008 at 10:42 PM, Raz <[EMAIL PROTECTED]> 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 [EMAIL PROTECTED] >>>> Please read the FAQ at http://kernelnewbies.org/FAQ >>>> >>>> >>> >> >> -- >> To unsubscribe from this list: send an email with >> "unsubscribe kernelnewbies" to [EMAIL PROTECTED] >> Please read the FAQ at http://kernelnewbies.org/FAQ >> >> > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [EMAIL PROTECTED] Please read the FAQ at http://kernelnewbies.org/FAQ Get rid of Add-Ons in your email ID get [EMAIL PROTECTED] Sign up now! http://in.promos.yahoo.com/address
