You should also use the trap command to reset the stty settings if the script is interrupted while running. Otherwise, your terminal session will be left hosed if you interrupt it while it is waiting for input.
the command in the single quotes will be executed if any of those signals are received. Some common signals:
SIGHUP (1) Hang up.
SIGINT (2) Interrupt from keyboard. Issued if you press ^C.
SIGQUIT (3) Quit from keyboard. Issued if you press ^D.
SIGFPE (8) Floating point exception.
SIGKILL (9) Kill signal.
SIGTERM (15) Terminate. Cause the program to quit gracefully
SIGCHLD (17) Child terminate.
I am doing a project in C program which requires to type in password in Unix terminal. Does anybody know how to shade or not output any words typed by user in the terminal?
I use the function scan() to read typing from user. Thanks in advance. (2 Replies)
Hi there,
How can I send a script to a remote ssh client.
1) I cannot connect through ftp
2) I just need to read a file on a remote server.
Here is what I do:
~$ ssh santiago@myserver.com
santiago@myserver.com's password:
santiago@myserver:~$ cat logfile
hello world
bonjour le monde
hola... (1 Reply)
Hello all,
I need to encrypt and save a password in a file and later decrypt to determine the original password string. Please suggest how can I use the linux commands or other approach to accomplish this.
Thanks for your help. (1 Reply)
Hello,
I have a paramter file, In which I store all the user-ids and passwords for the project. So if a user just invokes the paramter file he has access to all the variables, which i have exported in the parmatere file.
Now if a user echo's the variable which stores the databse password.... (1 Reply)
hi guys need some help. when ever i'm login ssh to aix server session always closed.
when trying t0 type wrong password the session still continues, but we tried the correct password it automatically ends.
what could be the problem to this
please see .profile details
... (6 Replies)
Hi,
I have a SQL which i want to run through a shell script.
query_result=`/home/oracle/product/11.2.0/bin/sqlplus -S uname/pwd@DBNAME <<!
set heading off feedback off trimspool on
set pagesize 0
set linesize 9999
spool $PARAM_PATH/param_name.txt;
Select sysdate from dual;
spool off;... (6 Replies)
Hello,
I have few files on unix which are payroll related and I need them to encrypt with password so others wouldn't see the data. I use ETL tool and would like to know the unix command that does encryption/decryption to use in the ETL.
Thank you,
Sri (3 Replies)
Discussion started by: eskay
3 Replies
LEARN ABOUT V7
signal
SIGNAL(2) System Calls Manual SIGNAL(2)NAME
signal - catch or ignore signals
SYNOPSIS
#include <signal.h>
(*signal(sig, func))()
(*func)();
DESCRIPTION
A signal is generated by some abnormal event, initiated either by user at a typewriter (quit, interrupt), by a program error (bus error,
etc.), or by request of another program (kill). Normally all signals cause termination of the receiving process, but a signal call allows
them either to be ignored or to cause an interrupt to a specified location. Here is the list of signals with names as in the include file.
SIGHUP 1 hangup
SIGINT 2 interrupt
SIGQUIT 3* quit
SIGILL 4* illegal instruction (not reset when caught)
SIGTRAP 5* trace trap (not reset when caught)
SIGIOT 6* IOT instruction
SIGEMT 7* EMT instruction
SIGFPE 8* floating point exception
SIGKILL 9 kill (cannot be caught or ignored)
SIGBUS 10* bus error
SIGSEGV 11* segmentation violation
SIGSYS 12* bad argument to system call
SIGPIPE 13 write on a pipe or link with no one to read it
SIGALRM 14 alarm clock
SIGTERM 15 software termination signal
16 unassigned
The starred signals in the list above cause a core image if not caught or ignored.
If func is SIG_DFL, the default action for signal sig is reinstated; this default is termination, sometimes with a core image. If func is
SIG_IGN the signal is ignored. Otherwise when the signal occurs func will be called with the signal number as argument. A return from the
function will continue the process at the point it was interrupted. Except as indicated, a signal is reset to SIG_DFL after being caught.
Thus if it is desired to catch every such signal, the catching routine must issue another signal call.
When a caught signal occurs during certain system calls, the call terminates prematurely. In particular this can occur during a read or
write(2) on a slow device (like a typewriter; but not a file); and during pause or wait(2). When such a signal occurs, the saved user sta-
tus is arranged in such a way that when return from the signal-catching takes place, it will appear that the system call returned an error
status. The user's program may then, if it wishes, re-execute the call.
The value of signal is the previous (or initial) value of func for the particular signal.
After a fork(2) the child inherits all signals. Exec(2) resets all caught signals to default action.
SEE ALSO kill(1), kill(2), ptrace(2), setjmp(3)DIAGNOSTICS
The value (int)-1 is returned if the given signal is out of range.
BUGS
If a repeated signal arrives before the last one can be reset, there is no chance to catch it.
The type specification of the routine and its func argument are problematical.
ASSEMBLER
(signal = 48.)
sys signal; sig; label
(old label in r0)
If label is 0, default action is reinstated. If label is odd, the signal is ignored. Any other even label specifies an address in the
process where an interrupt is simulated. An RTI or RTT instruction will return from the interrupt.
SIGNAL(2)