05-07-2009
: is an alias for "true". See "man true" (though it is also built into ksh). It is a command which does nothing and returns exit status 0. The loop will keep going until it is exited.
In the second example the ":" is being used cleverly as a null command to allow the "${ans:=y}" default substitution to work without giving a syntax error.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
I have a file with 3 columns. Often the first two will hold the same values and the third may differ. I only want one row for each.
i.e.
aaa,bbb,1
aaa,bbb,2
aaa,bbb,3
xxx,yyy,1
xxx,yyy,2
zzz,rrr,5
Should be
aaa,bbb,1
xxx,yyy,1
zzz,rrr,5
I just want the first instance of... (20 Replies)
Discussion started by: peter.herlihy
20 Replies
2. UNIX for Dummies Questions & Answers
I need to copy my Live Db Instance to my Test Db Instance
Can somebody please tell me the easiest way to go about this
It is an Informix Database running on HP-UX
Thanks (0 Replies)
Discussion started by: cobdeng
0 Replies
3. Linux
hi frnds
here i m trying to configure OTRS instance but i m getting the following error message
while runnning through browser.
I m writing the following http://192.168.1.55:8080/otrs2/index.pl
"
#!/usr/bin/perl -w... (7 Replies)
Discussion started by: naik_mit
7 Replies
4. Shell Programming and Scripting
Hi,
I have a script. I want only one instance of the script to be running at any point of the time. How can I do it.
what would be the exact format of the ps command for doing this. For example the name of my script is "Inst.sh"
Thanx in advance (2 Replies)
Discussion started by: sendhil
2 Replies
5. Shell Programming and Scripting
Alright, I think I know what I am doing with sed(which probably means I don't). But I cant figure out how to replace just the first occurance of a string. I have tried sed, ed, and grep but can't seem to figure it out. If you have any suggestions I am open to anything! (3 Replies)
Discussion started by: IronHorse7
3 Replies
6. Shell Programming and Scripting
Hi All,
I have a property in a file as:
property=value=a
If I use FS="=" then I want only first = to be considered as field separator and remaining as value
echo -e "property=value=a" | awk -F= '{print $2}'
ie my $2 should be value=a
Can anyone please help me with this. I need it in... (3 Replies)
Discussion started by: gurukottur
3 Replies
7. Shell Programming and Scripting
Hi, I've been trying to figure this one out and found a post about this on the forum here but the solution didn't seem to work for me. Basically what I have is a file that looks something like:
stuff
morestuff
0
otherthing
0
etc
I want to substitute for the 0 but what I want to... (9 Replies)
Discussion started by: eltinator
9 Replies
8. Red Hat
Hi ,
Maximum How many instances of apache can we run in
one box? (2 Replies)
Discussion started by: krish4linux
2 Replies
9. Shell Programming and Scripting
Hi All,
I have a input file like
1| abc
1| abcd
1| abcde
2| abc
2| abcd
3| abcde
I want the output like
1| abcde
2| abcde
Any help would be highly appreciated.
Thanks in advance. (9 Replies)
Discussion started by: lrkp
9 Replies
10. UNIX for Advanced & Expert Users
Hi,
I want to get the only application name from the server.
Ex:
if i give $ ps -ef | grep bw.
It will show all BW process with entire path. It will little confuse to list out the process. Can anyone have syntax to get only the instance name. I need this for be, hawk,ems also.
Please... (2 Replies)
Discussion started by: ckchelladurai
2 Replies
LEARN ABOUT OPENDARWIN
shell
shell(1F) FMLI Commands shell(1F)
NAME
shell - run a command using shell
SYNOPSIS
shell command [command] ...
DESCRIPTION
The shell function concatenate its arguments, separating each by a space, and passes this string to the shell ($SHELL if set, otherwise
/usr/bin/sh).
EXAMPLES
Example 1: A sample output of shell command.
Since the Form and Menu Language does not directly support background processing, the shell function can be used instead.
`shell "build prog > /dev/null &"`
If you want the user to continue to be able to interact with the application while the background job is running, the output of an exe-
cutable run by shell in the background must be redirected: to a file if you want to save the output, or to /dev/null if you don't want to
save it (or if there is no output), otherwise your application may appear to be hung until the background job finishes processing.
shell can also be used to execute a command that has the same name as an FMLI built-in function.
NOTES
The arguments to shell will be concatenate using spaces, which may or may not do what is expected. The variables set in local environments
will not be expanded by the shell because "local" means "local to the current process."
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
sh(1), attributes(5)
SunOS 5.10 5 Jul 1990 shell(1F)