Sponsored Content
Top Forums Shell Programming and Scripting how to take input at the startup script!! Post 302172083 by Perderabo on Sunday 2nd of March 2008 10:28:38 AM
Old 03-02-2008
Quote:
Originally Posted by adderek
But in my opinion this is not a good thing.
I have the same opinion. To the kernel, the definition of a daemon is a process with no controlling terminal. Daemons show up with a ? in the tty field on most implementations of ps. When a daemon opens a tty, that tty becomes it's controlling terminal. It is no longer a daemon nor will any child processes be daemons. As one example of the many problems this will cause, if you type a control c on that terminal all processes with that controlling will get an INTR unless they are ignoring that signal.

You can avoid this by forking a subprocess to open the terminal, do the tty io, pass the data back to the parent via a file or pipe, and then exit. You must also ensure that this is completed prior to any login prompt appearing on the terminal.

This is why daemons fork to write a message on the console. Becoming a daemon again is not possible, but with the right sequence of operations including several forks(), a process can arrange for a descendant process to be created as a daemon.

Avoiding the non-daemon trap will still leave the problem that the user must be present at reboot time, but at least the system should be working.
 

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Startup script

New in Unix, I am adding a line "route add 57.14.y.y 57.14.x.x" every day after rebooting the system. Where can I add the line so during boot up (the system is re-started every day by design (???) the line is executed? (I tried the /etc/rc2.d/S90 but for some reason the line needs to be added... (2 Replies)
Discussion started by: texaspanama
2 Replies

2. HP-UX

Executing a script at startup

Hi, I want a script to execute as soon as a user logs in(instead of directing to his home directory). i know that i have to mention the path of script in the user's .profile to execute this, but not sure where and what to edit. I just tried and was unsuccesful. Kindly provide the code that i... (4 Replies)
Discussion started by: sridharr83
4 Replies

3. AIX

run script at startup

I am using AIX 5.3 in P6 machine. I have a script "test.sh", when i run it manually it runs properly. I want to run the script automatically when system starts. I kept the script in /etc/rc.d/init.d and also in /etc/rc.d/rc2.d but it is not working. Do i have to write it in inittab instead of... (1 Reply)
Discussion started by: pchangba1
1 Replies

4. UNIX for Dummies Questions & Answers

Startup Script Somewhere ?

Hello there! I need help. Everytime I login to my ssh, i see this: -bash: .export: command not found -bash: .export: command not found -bash: .export: command not found -bash: .export: command not found any help ? thanks (0 Replies)
Discussion started by: fbauto1
0 Replies

5. AIX

startup script

Hi I need the below script to be started whenever I reboot my aix server ? #cat cdbegin /cdirect/cdunix/ndm/bin/cdpmgr -i /cdirect/cdunix/ndm/cfg/cbspsdb01/initparm.cfg Please suggest how to add this to the startup ? (2 Replies)
Discussion started by: samsungsamsung
2 Replies

6. Shell Programming and Scripting

Script to delete files with an input for directories and an input for path/file

Hello, I'm trying to figure out how best to approach this script, and I have very little experience, so I could use all the help I can get. :wall: I regularly need to delete files from many directories. A file with the same name may exist any number of times in different subdirectories.... (3 Replies)
Discussion started by: *ShadowCat*
3 Replies

7. Shell Programming and Scripting

Startup and shutdown script

Hi all, I'm writing a script to stop & start oracle: su - oracle -c "sqlplus / as sysdba" -c "shutdown immediate">> ${log} 2>&1 The {log} refers to the log file. The part in bold gives error: /usr/sbin/shutdown: Only root can run /usr/sbin/shutdown Pls suggest how to correct this. ... (5 Replies)
Discussion started by: frum
5 Replies

8. Shell Programming and Scripting

Apache tomcat startup script not booting at startup.

I copied the script from an AskUbuntu post - #!/bin/bash ### BEGIN INIT INFO # Provides: tomcat7 # Required-Start: $network # Required-Stop: $network # Default-Start: 2 3 4 5 # Default-Stop: 0 1 6 # Short-Description: Start/Stop Tomcat server ### END INIT INFO ... (14 Replies)
Discussion started by: Hijanoqu
14 Replies

9. Shell Programming and Scripting

Startup script

I can't quite find a clear answer on how to properly write a start up script. Does anybody have any ideas?? (3 Replies)
Discussion started by: Huitzilopochtli
3 Replies
RBASH(1)						      General Commands Manual							  RBASH(1)

NAME
rbash - restricted bash, see bash(1) RESTRICTED SHELL
If bash is started with the name rbash, or the -r option is supplied at invocation, the shell becomes restricted. A restricted shell is used to set up an environment more controlled than the standard shell. It behaves identically to bash with the exception that the follow- ing are disallowed or not performed: o changing directories with cd o setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV o specifying command names containing / o specifying a file name containing a / as an argument to the . builtin command o specifying a filename containing a slash as an argument to the -p option to the hash builtin command o importing function definitions from the shell environment at startup o parsing the value of SHELLOPTS from the shell environment at startup o redirecting output using the >, >|, <>, >&, &>, and >> redirection operators o using the exec builtin command to replace the shell with another command o adding or deleting builtin commands with the -f and -d options to the enable builtin command o using the enable builtin command to enable disabled shell builtins o specifying the -p option to the command builtin command o turning off restricted mode with set +r or set +o restricted. These restrictions are enforced after any startup files are read. When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script. SEE ALSO
bash(1) GNU Bash-4.0 2004 Apr 20 RBASH(1)
All times are GMT -4. The time now is 04:10 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy