Negative Offset

DNAx86 · #1 (**permalink**) 05-09-2008

Function: int fcntl(int fd, int cmd, struct flock * lock)

Data Type: struct flock
This structure is used with the fcntl function to describe a file lock. It has these members:

off_t l_start
This specifies the offset of the start of the region to which the lock applies, and is given in bytes relative to the point specified by l_whence member.

off_t l_len
This specifies the length of the region to be locked. A value of 0 is treated specially; it means the region extends to the end of the file.

Can I set negative offset to l_start?

jim mcnamara · #2 (**permalink**) 05-09-2008

off_t is a typedef for long (C99 standard) so, yes it can be negative if the l_whence is SEEK_CUR or SEEK_END

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
Reading a file from a specified offset	saurabhsinha23	UNIX for Dummies Questions & Answers	2	12-13-2007 12:52 PM
negative permissions	sickoboy	UNIX for Dummies Questions & Answers	4	10-12-2006 09:49 PM
offset - informix chunk	shibz	UNIX for Dummies Questions & Answers	1	01-27-2003 11:44 AM
Accessing substrings by offset and length	Vishnu	High Level Programming	2	10-17-2002 10:07 AM
negative UID/GID?!! I can see 'em but what the hell do they mean?!	hellz	UNIX for Dummies Questions & Answers	2	09-07-2001 03:18 PM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:


	Powered by