Signal catching

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Catching error in sftp

Hi All Experts, I have a script which logs to the server via sftp connection with below code :- user_name@sftp_server.com and the connection is going smooth. My requirement is to place file in sftp_server in some path. and if path doesn't exist or the file is not put successfully I...

2. Shell Programming and Scripting

Quiting running process without catching TRAP signal

Hi, I would like to ask, if is it possible to quit running loop in the script any other way than catching the trap signal. Ctrl-C ends only current running instance of process but not whole script. Any clues?

3. Shell Programming and Scripting

Catching errors

Hi, I'm writing a scheduling script which will co-ordinate the launching of scripts. This script is scheduling based on an input file, and launches the appropriate scripts at the right times. The only issue I'm having is: - if a script dies, or even has a syntax error, I want to catch...

4. Programming

catching a signal from child process

i am creating children processes using fork system call every child i create goes to sleep for random time. when child stops running how can i catch his signal and turminate the child

5. Shell Programming and Scripting

catching some errors

I need to find a way to keep a running tally of how many times events or actions occur. Say if a user is prompted to make inputs of 1 or 2, I want it to keep track of how many times 1 was entered, and how many times 2 was entered. Thanks for your help

6. Shell Programming and Scripting

Catching all Exit Codes

I have a Unix Script that has several exit in the middle. each returning seperate exit codes. I have to catch all the exit's and perform an operation say "Mail the status code" before the actual code completes. How can i do this in KSH ?

7. UNIX for Dummies Questions & Answers

Awk- catching the last two chars

Can anyone explain to me how to get the last two chars' from each row of Column (each row being variable in length) using awk, some of the lines will be blank, I'll be running a paste after awking. So I need to keep the blanks where they are..so I can paste back all columns in the correct order ...

8. Programming

Catching signal and piping

Hi, Recently I was reading some c coding by some colleagues and I noticed that the above trend. They will create a pipe for the process then they will use the standard signal handler to capture a particular signal and write that signal to the pipe. On the other end, the process will read the...

9. UNIX for Dummies Questions & Answers

catching interrupts

hey i have been facing a problem,can you tell me if we can catch ctrl d in unix i have tried and sucessfully catched and disabled ctrl-c and ctrl -z but am not sure if we can do the same for CTRL-D, so got any clue mail on he forum or ...i mean c programming in Unix thats what i am working on

LEARN ABOUT OSF1

sigsuspend

sigsuspend(2)							System Calls Manual						     sigsuspend(2)

NAME

       sigsuspend - Atomically changes the set of blocked signals and waits for a signal

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <signal.h>

       int sigsuspend (
	       const sigset_t *signal_mask );

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       sigsuspend():  XPG4, XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Points to a set of signals.

DESCRIPTION

       The sigsuspend() function replaces the signal mask of the process (or thread) with the set of signals pointed to by the signal_mask parame-
       ter, and then suspends execution of the caller until delivery of a signal whose action is either to execute a signal-catching  function	or
       to terminate the process.  The sigsuspend() function does not allow the SIGKILL or SIGSTOP signals to be blocked.  If a program attempts to
       block one of these signals, the sigsuspend() function gives no indication of the error; the illegal request is simply ignored.

       If delivery of a signal causes the process to terminate, the sigsuspend() function does not return. If delivery of a signal causes  a  sig-
       nal-catching  function  to  execute,  the  sigsuspend()	function  returns after the signal-catching function returns, with the signal mask
       restored to the set that existed prior to the call to the sigsuspend() function.

       The sigsuspend() function sets the signal mask and waits for an unblocked signal as one atomic operation. This means  that  signals  cannot
       occur  between  the  operations of setting the mask and waiting for a signal.  If a program invokes sigprocmask(SIG_SETMASK) and sigpause()
       separately, a signal that occurs between these functions might not be noticed by sigpause().

       In normal usage, a signal is blocked by using the sigprocmask(SIG_BLOCK,...)  or pthread_sigmask(...)  function at the beginning of a crit-
       ical section. The process then determines whether there is work for it to do. If no work is to be done, the process waits for work by call-
       ing the sigsuspend() function with the mask previously returned by the sigprocmask() function.

NOTES

       The sigpause() function is provided for compatibility with older UNIX systems; its function is a subset of the sigsuspend() function.

RETURN VALUES

       Since the sigsuspend() function suspends process execution indefinitely, there is no successful	completion  return  value.   If  a  return
       occurs, -1 is returned and errno is set to indicate the error.

ERRORS

       The  sigsuspend()  function  sets errno to the specified values for the following conditions: A signal is caught by the calling process and
       control is returned from the signal-catching function.

RELATED INFORMATION

       Functions: pause(3), sigaction(2), sigblock(2), sigprocmask(2), sigvec(2)

       Standards: standards(5) delim off

																     sigsuspend(2)

Programming