...we must accompany the check with the return value of the function.
For instance:
Kind of, but you seem to just be checking for a specific error. Generally for *NIX system calls:
The return value tells you whether there was an error or not, and
errno tells you the specific type of error.
Also, be aware that you wrote "fd = -1" not "fd == -1", which is always false - not sure if this is a typo, but make sure you understand why this is an error. I always like to write the constant on the left-hand side of the comparison to try and avoid this sort of thing.
Summing up:
This User Gave Thanks to JohnGraham For This Post:
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)
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)
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)
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)
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)
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)
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)
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)
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
LEARN ABOUT CENTOS
tcl_geterrno
Tcl_SetErrno(3) Tcl Library Procedures Tcl_SetErrno(3)__________________________________________________________________________________________________________________________________________________NAME
Tcl_SetErrno, Tcl_GetErrno, Tcl_ErrnoId, Tcl_ErrnoMsg - manipulate errno to store and retrieve error codes
SYNOPSIS
#include <tcl.h>
void
Tcl_SetErrno(errorCode)
int
Tcl_GetErrno()
const char *
Tcl_ErrnoId()
const char *
Tcl_ErrnoMsg(errorCode)
ARGUMENTS
int errorCode (in) A POSIX error code such as ENOENT.
_________________________________________________________________DESCRIPTION
Tcl_SetErrno and Tcl_GetErrno provide portable access to the errno variable, which is used to record a POSIX error code after system calls
and other operations such as Tcl_Gets. These procedures are necessary because global variable accesses cannot be made across module bound-
aries on some platforms.
Tcl_SetErrno sets the errno variable to the value of the errorCode argument C procedures that wish to return error information to their
callers via errno should call Tcl_SetErrno rather than setting errno directly.
Tcl_GetErrno returns the current value of errno. Procedures wishing to access errno should call this procedure instead of accessing errno
directly.
Tcl_ErrnoId and Tcl_ErrnoMsg return string representations of errno values. Tcl_ErrnoId returns a machine-readable textual identifier such
as "EACCES" that corresponds to the current value of errno. Tcl_ErrnoMsg returns a human-readable string such as "permission denied" that
corresponds to the value of its errorCode argument. The errorCode argument is typically the value returned by Tcl_GetErrno. The strings
returned by these functions are statically allocated and the caller must not free or modify them.
KEYWORDS
errno, error code, global variables
Tcl 8.3 Tcl_SetErrno(3)