Signal Default Action Post: 302147629

Sponsored Content

Top Forums Programming Signal Default Action Post 302147629 by matrixmadhan on Wednesday 28th of November 2007 12:19:15 AM

11-28-2007

Registered User

Quote:

The sigaction() function provides a more comprehensive and reliable mechanism for controlling signals; new applications should use sigaction() rather than signal().

I perfectly agree with the above and have been using that only.

Am just curious to know about the behavior of signal(); and why its behavior is different in different systems.

Is it due to the reason that different libraries are in use ? If so, how to identify them ?

Quote:

from occurring until the current signal handling has completed

Am confused about this too, there is no guarantee with the older semantics that the signal of same type will not be delivered while the current function block for the signal is being executed.

In that case, there is no reason for it to wait till the function block is executed.

In short, can it be said signal() behavior is undefined - or am I being rude in saying that ?

matrixmadhan

View Public Profile for matrixmadhan

Find all posts by matrixmadhan

6 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

any idea to repeat a action in VI

Any idea to repeat an action to all the lines in vi... suppose i want to delete the first word from all the lines in VI .. how would i do it ? in general i am also looking for a way to apply a action to all the lines in VI .

2. Shell Programming and Scripting

action command

Hi.. When i refered the script /etc/rc.sysinit... i found the "action commands" like But this is not working in my shells.. the following error is coming... Please anybody help Thanks in advance esham

3. Shell Programming and Scripting

same action in then as in else: explanation?

in /etc/init.d/networking of an ubuntu computer, I found this code: if ifdown -a --exclude=lo; then log_action_end_msg $? else log_action_end_msg $? fi Shouldn't it be replace by ifdown -a --exclude=lo ...

4. Shell Programming and Scripting

Need help with find its action

I am writing a shell script that takes at least 2 arguments. The first is an octal representation of file permissions, the second is a command that is executed on all the files found with that permission. #!/bin/sh find . -perm $1 -exec $2 $3 $4 {} \; invoked: ./script.sh 543 ls -la what...

5. AIX

Received signal #11, SIGSEGV [default] on AIX 6.1

Hello, One of our customer is getting segmentation fault when he runs his shell script which invokes our executable on AIX 6.1. On AIX 5.3, there were no issues. Here is the truss output. 811242: __loadx(0x0A040000, 0xF0D3A26C, 0x00000000, 0x00000009, 0x00000000) = 0xF026E884...

6. Shell Programming and Scripting

multiple action!

lets explain it easy by showing the initial file and desired file: I've a file such this that contains: initial_file: 31/12/2011 23:46:08 38.6762 43.689 14.16 Ml 3.1 ...

LEARN ABOUT LINUX

sysv_signal

SYSV_SIGNAL(3)						     Linux Programmer's Manual						    SYSV_SIGNAL(3)

NAME

       sysv_signal - signal handling with System V semantics

SYNOPSIS

       #define _GNU_SOURCE
       #include <signal.h>

       typedef void (*sighandler_t)(int);

       sighandler_t sysv_signal(int signum, sighandler_t handler);

DESCRIPTION

       The sysv_signal() function takes the same arguments, and performs the same task, as signal(2).

       However	sysv_signal() provides the System V unreliable signal semantics, that is: a) the disposition of the signal is reset to the default
       when the handler is invoked; b) delivery of further instances of the signal is not blocked while the signal handler is executing; and c) if
       the handler interrupts (certain) blocking system calls, then the system call is not automatically restarted.

RETURN VALUE

       The sysv_signal() function returns the previous value of the signal handler, or SIG_ERR on error.

ERRORS

       As for signal(2).

CONFORMING TO

       This function is nonstandard.

NOTES

       Use of sysv_signal() should be avoided; use sigaction(2) instead.

       On  older  Linux systems, sysv_signal() and signal(2) were equivalent.  But on newer systems, signal(2) provides reliable signal semantics;
       see signal(2) for details.

       The use of sighandler_t is a GNU extension; this type is only defined if the _GNU_SOURCE feature test macro is defined.

SEE ALSO

       sigaction(2), signal(2), bsd_signal(3), feature_test_macros(7), signal(7)

COLOPHON

       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

								    2007-05-04							    SYSV_SIGNAL(3)