07-07-2005
Quote:
Test result (ksh):
$ print "abc cde efg" | { read k l ; print "k=$k, l=$l" ; }
k=, l=
I am in puzzle about this. Can somebody tell me why?
10 More Discussions You Might Find Interesting
1. Programming
Hi,
Can any one please help me with this. Am struggling hard to get a solution.
I am doing telnet through a C program and getting the stdout file descriptor of the remote machine to pipe.
read() function is getting data, But whenl it receives SOH character ie. ^A ( Start of heading = Console... (2 Replies)
Discussion started by: JDS
2 Replies
2. Programming
I know how to read and write if i have a forked process with only one child. However what is involved with reading and writing with many forked processes. Say one parent that forks 5 children, and needs to communicate with all 5 in half duplex.
int temp, counter=0;
do{
pipe(temp);
... (5 Replies)
Discussion started by: steveneliuk
5 Replies
3. UNIX for Advanced & Expert Users
I have the following code which works on AIX 4.3 but fails at times on AIX 5.3
with:
cat: 0652-054 cannot write to output. There is no process to read data written to a pipe.
validator="${validator_exe} ${validator_parms}"
cmd_line="${CAT} ${data_file} | ${validator}... (6 Replies)
Discussion started by: vigsgb
6 Replies
4. AIX
Hi Everyone,
The machine I'm working on is an AIX 5.3 LPAR running on a P650. oslevel -r shows 5300-08. I'm trying to take a backup to a SCSI tape drive, which has been working up until this point. I know of nothing that has changed recently to cause this problem. But when I try to take a... (0 Replies)
Discussion started by: need2bageek
0 Replies
5. Shell Programming and Scripting
I have a perl program that I want to read from a file passed as an argument or from a pipe. If their is no pipe or arguments, I want it to output a help message. I am stuck on how to prevent perl from reading from the keyboard if it isn't fed any file names or data from a pipe. The only things I... (4 Replies)
Discussion started by: ilikecows
4 Replies
6. UNIX for Dummies Questions & Answers
We use SAP application cluster on AIX. Communication between 2 of its instances is failing randomly with the following error:
java.net.SocketException: There is no process to read data written to a pipe.
The above error causes a cluster restart if an important communication fails.
Can... (0 Replies)
Discussion started by: RoshniMehta
0 Replies
7. Shell Programming and Scripting
I have a file data_1.out which contains:
1|abc mail|mail subject|mail body
2|def mail|mail subject|def mail body
I am trying to read the variables from data_1.out and use them to print to 2 different files based on the id (first_column)
The problem is I am not able to read the file... (8 Replies)
Discussion started by: sol_nov
8 Replies
8. Shell Programming and Scripting
Hello,
I need to read the pipe data as:-
cat abc.txt | uuencode abc.txt | mailx -s hi xyz@xyz.com
I will override the mailx function so that when mailx is called, it calls my version of maix and in that function I want to read the file which is attached in progional mailx function- abc.txt... (7 Replies)
Discussion started by: shubh05
7 Replies
9. Shell Programming and Scripting
Hello,
I have an ffmpeg bash script which is working nice and
I need to do the same for other sources.
To create new scripts and to deal with multiple bash files sounds not logical. It is a bit hard to manage for me..
I wondered if it was possible to make my input file as variable.
Then I... (1 Reply)
Discussion started by: baris35
1 Replies
10. UNIX for Beginners Questions & Answers
Hi All,
I'm creating a program which reads millions of bytes from the PIPE and do some processing. As the data is more, the idea is to read the pipe parallely.
Sun Solaris 8
See the code below:
#!/bin/sh
MAXTHREAD=30
awk '{print $1}' metadata.csv > nvpipe &
while
do
... (3 Replies)
Discussion started by: mr_manii
3 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)
NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$SHELL -c". This doesn't work as intended:
ssh host touch 'hi there' # fails
It creates 2 files, hi and there. Instead, do this:
cmd=`shell-quote touch 'hi there'`
ssh host "$cmd"
This gives you just 1 file, hi there.
process find output
It's not ordinarily possible to process an arbitrary list of files output by find with a shell script. Anything you put in $IFS to
split up the output could legitimately be in a file's name. Here's how you can do it using shell-quote:
eval set -- `find -type f -print0 | xargs -0 shell-quote --`
debug shell scripts
shell-quote is better than echo for debugging shell scripts.
debug() {
[ -z "$debug" ] || shell-quote "debug:" "$@"
}
With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote you can.
save a command for later
shell-quote can be used to build up a shell command to run later. Say you want the user to be able to give you switches for a command
you're going to run. If you don't want the switches to be re-evaluated by the shell (which is usually a good idea, else there are
things the user can't pass through), you can do something like this:
user_switches=
while [ $# != 0 ]
do
case x$1 in
x--pass-through)
[ $# -gt 1 ] || die "need an argument for $1"
user_switches="$user_switches "`shell-quote -- "$2"`
shift;;
# process other switches
esac
shift
done
# later
eval "shell-quote some-command $user_switches my args"
OPTIONS
--debug
Turn debugging on.
--help
Show the usage message and die.
--version
Show the version number and exit.
AVAILABILITY
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions.
AUTHOR
Roderick Schertler <roderick@argon.org>
perl v5.16.3 2010-06-11 SHELL-QUOTE(1)