Visit The New, Modern Unix Linux Community


Function open() sets errno


 
Thread Tools Search this Thread
Top Forums Programming Function open() sets errno
# 8  
Quote:
Originally Posted by JohnGraham
Also, be aware that you wrote "fd = -1" not "fd == -1", which is always false
I'm sure it was just a momentary lapse, but to avoid confusing anyone: assigning -1 is a boolean true.

Regards,
Alister
This User Gave Thanks to alister For This Post:
# 9  
Thanks JohnGraham for the suggestions.
Missing one "=" was a typing mistake.



---------- Post updated at 07:57 PM ---------- Previous update was at 07:56 PM ----------

Thanks JohnGraham for the suggestions.
Missing one "=" was a typing mistake.
# 10  
Quote:
Originally Posted by alister
I'm sure it was just a momentary lapse, but to avoid confusing anyone: assigning -1 is a boolean true.
Of course - d'oh! Apologies if anyone was confused...
# 11  
  • If you are doing simple or poll()/select() driven synchronous blocking I/O, all the errno get the same treatment with different messages.
  • If you do fcntl O_NONBLOCK (O_NDELAY looks like an old mistake) non-blocking, you have to sort out the EAGAIN from would block situations.
  • For some devices and raw I/O, you need to retry on EINTR. (BTW, some situations can also give read() and the like a zero return from an empty framed block, a false EOF that needs to be retried.)
This User Gave Thanks to DGPickett For This Post:

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #722
Difficulty: Medium
Konrad Zuse built the first digital freely programmable computer, the Z1.
True or False?

9 More Discussions You Might Find Interesting

1. HP-UX

Failed to open tape device /dev/rmt/0mn:Device busy (errno = 16)

Hi, Unable to make tape backup, please help. /opt/ignite/bin/make_tape_recovery -a /dev/rmt/?mn -I -v -m tar -x inc_entire=vg00 * Creating local directories for configuration files and archive. ======= 04/25/16 16:28:08 IST Started /opt/ignite/bin/make_tape_recovery. (Mon... (4 Replies)
Discussion started by: anuragr
4 Replies

2. Shell Programming and Scripting

Open file function

Hello all, just a quick little part of code i'm writing to check if the file i'm writing too in my automatic process is not being written too manually. #!/bin/bash FUSER=$(/sbin/fuser -s /toto.tmp >/dev/null 2>&1) LSOF=$(/usr/sbin/lsof | grep -q "toto.tmp") PGREP=$(pgrep -f "toto.tmp" >... (6 Replies)
Discussion started by: maverick72
6 Replies

3. Shell Programming and Scripting

Help !! perl open function

Help Please perl Gurus, I am trying to add ungrouped passengers in a group and I creating a script however it fails on first step only I tried all the options it returns following error. syntax error at junki line 4, near "open " Execution of junki aborted due to compilation errors. ... (2 Replies)
Discussion started by: dynamax
2 Replies

4. Programming

Open function of sys/stat.h

If a process already has the entire file locked for read and write using newstruct.l_type = F_WRLCK; what would happen if another process would try to open it in read only mode using open(filename, O_RDONLY); ? I want to check if the file exists and I want it to work even if another process has... (4 Replies)
Discussion started by: cyler
4 Replies

5. UNIX and Linux Applications

Sybase help: Open client, bcp function

To begin: I use Linux The Problem: I need bcp functionality for scripts. Perl modules, such as Sybase:xfer, require ctlib which comes with Sybase Open Client. Talking with Sybase sales reps is an exercise in futility and hate. They know absolutely nothing about their own products and will... (0 Replies)
Discussion started by: Bubnoff
0 Replies

6. Programming

errno

Hey, Can I assume that for certain function calls, errno can never be set to a certain value. More specifically, can I assume that for if the stat function call fails, the errno can never be or "No space left on device." I am assuming that a read function cannot fail because of no space... (5 Replies)
Discussion started by: the_learner
5 Replies

7. UNIX and Linux Applications

(lmgrd) Can't open /usr/tmp/.flexlm/lmgrdl.4081, errno: 24

We are a tool vendor and one of our users is getting this error. The user is using several macrovision(FLEXLM) license enabled products including ours. (lmgrd) Can't open /usr/tmp/.flexlm/lmgrdl.4081, errno: 24 At this time, it stops checking out licenses, and will not respond to query's.... (2 Replies)
Discussion started by: return_user
2 Replies

8. Virtualization and Cloud Computing

Clouds (Partially Order Sets) - Streams (Linearly Ordered Sets) - Part 2

timbass Sat, 28 Jul 2007 10:07:53 +0000 Originally posted in Yahoo! CEP-Interest Here is my follow-up note on posets (partially ordered sets) and tosets (totally or linearly ordered sets) as background set theory for event processing, and in particular CEP and ESP. In my last note, we... (0 Replies)
Discussion started by: Linux Bot
0 Replies

9. Shell Programming and Scripting

function to test if file is open

I need to write a function that will work in sh/ksh shell that will test to see if a file has already been opened for writting by another user has anyone written something like this? (3 Replies)
Discussion started by: johnsonbryce
3 Replies

Featured Tech Videos