<$path_to_dir tries to read from that as if it's a filename -- not as if it's a list of lines. Technically it's valid for a filename to have newlines in it, strangley enough! The only invalid characters for a filename are NULLs and forward slashes.
Depending on what shell you're using you could do:
Also, you should always, always quote your variables unless you want them to start splitting when they end up with spaces in them. No reason not to.
Hi,
Can anyone please help me: i'm trying to read a file with directory-names , then go to that directory and read another (output) file to perform some tasks per line (second read line in the part of script below).
The problem is that after the nested while loop has finished, the first while... (7 Replies)
HELLO all :),
I have been trying to use a simple while loop to read a file " templist", line by line and perform an action. See the code below. The reason for not using a while read line loop is the for the use of the if condition that wouldn't work. I would appreciate some ideas as this has... (2 Replies)
Hi All,
How can we use read line using the index value of a FOR loop?
eg:
pt_mstr,pt_status,8
pt_mstr,pt_buyer,8
pt_mstr,pt_sfty_stk,8
pt_mstr,pt_ord_pol,3
pt_mstr,pt_capacity,8
pt_mstr,pt_plan_ord,3
pt_mstr,pt_ord_mult,8
From this file i want to read the line2, 3 and 4 only using a FOR... (3 Replies)
Hi I'm writing a bash script which will read an input file and look for occurrences of the current user ($USER) executing the script. When i find the occurrence of the username I take that line and append it to a file with a line number and bracket display next to line.
The input file has been... (12 Replies)
Hi
I am using while loop, below, to read lines from a very large file, around 400,000 rows. The script works fine until around line 300k but then starts giving incorrect result.
I have tried running the script with a smaller data set and it works fine. I made sure to include the line where... (2 Replies)
I have written a script to read the file line by line.
It is reading and printing the lines.
But it is coming out of loop before reading last line.
So I am not able to print last line.
How do I solve it. (6 Replies)
Hi
As a newbe in scripting, i struggle hard with my first script.
What i want to do is, bringing data of two files together.
file1:
....
05/14/12-04:00:00 41253 4259 5135 5604 5812 5372
05/14/12-04:10:00 53408 5501 6592 7402 7354 6639
05/14/12-04:20:00 58748 6037 7292 8223... (13 Replies)
I'm looking for some help in figuring why my little bit of code will not process any entries other then the first one in my list.
while read line ;do
hostname=${line//\"}
a=`ssh user@$hostname uptime;echo $?`
if ];then
dt=`date`
touch... (6 Replies)
Based on text file:
PATH:/media/hdd/Media/Video/title1 FILE:/media/cache/281662-14.jpg
PATH:/media/hdd/Media/Video/title2 FILE:/media/cache/281662-15.jpg
PATH:/media/hdd/Media/Video/title3 FILE:/media/cache/281662-16.jpg
PATH:/media/hdd/Media/Video/title4 FILE:/media/cache/281662-17.jpg... (12 Replies)
while read -a line; this is not working in ksh. what is the equivalent of this in ksh.
read: -a: unknown option (2 Replies)
Discussion started by: archana25
2 Replies
LEARN ABOUT DEBIAN
shell-quote
SHELL-QUOTE(1p) User Contributed Perl Documentation SHELL-QUOTE(1p)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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 v5.8.4 2005-05-03 SHELL-QUOTE(1p)