A shell script is a script written for the shell, or command line interpreter, of an operating system.
5
votes
4answers
129 views
Show sum of file sizes in directory listing
The Windows dir directory listing command has a line at the end showing the total amount of space taken up by the files listed. For example, dir *.exe shows all the .exe files in the current ...
5
votes
1answer
604 views
“echo 1 > /sys/block/sdX/device/delete” on all disks except predetermined list
I have a list of scsi disks that I need to remove. The list is considered random at best and changes from time to time. I want to remove everything except a predefined list that I have created. Let's ...
5
votes
2answers
1k views
Mass .flac --> .mp3 transcoding: How to write a shell script that preserves ID3 tag information?
In recent weeks I've gone from a fairly 'hands-on' approach to .flac --> .mp3 transcoding, to one that's far more 'set & forget'.
The first step was to stop using a GUI front end (Audacity with a ...
5
votes
2answers
35 views
Modifying zsh globbing patterns to use with cp
I'm trying to write a script to copy files recursively from a particular folder except files A.extn, B/*.extn and C/* where B and C are directories and extn is just some generic extension. This is ...
5
votes
4answers
142 views
Check if folder is a mounted remote filesystem
What is the best way (reliable, portable, etc.) to check if a given folder is on a mounted remote (nfs) filesystem within a shell script?
I am looking for a command that would look like:
...
5
votes
2answers
71 views
Why does set -e not work inside () ||
I've run across some scripting like this recently:
( set -e ; do-stuff; do-more-stuff; ) || echo failed
This looks fine to me, but it does not work! The set -e does not apply, when you add the ||. ...
5
votes
2answers
440 views
How to continuously take backup of log files?
I have some applications in Lunux which creates Log files of around 41 MB each. The log files switches from log.1 to log.2 and starts overwriting log.2 once this 41MB is completed in log.1 file.
I ...
5
votes
1answer
563 views
Running cron script with lynx fails to work
I'm trying to automate a login process that can only be done through a browser. I am using the lynx browser to script the actions required to do this. Lynx does this by dumping a user's keystrokes ...
5
votes
3answers
2k views
ssh input from text file
These two question is driving me crazy and I don't have good expertise of ssh. (but I suspect it is to do with redirection only)
The questions are,
You want to pass multiple lines of input from a ...
4
votes
3answers
919 views
How to kill two or more processes with one kill command?
I am using the following command to kill one java process via shell script:
pidof java|xargs kill -9 $1
What if the list of pidof output has more than one elements? How do I kill them both with ...
4
votes
2answers
468 views
What's a safe and portable way to split a string in shell programming?
When writing a shell script, I often want to split a string. Here's a very simple example:
for dir in $(echo $PATH | tr : " "); do
[[ -x "$dir"/"$1" ]] && echo $dir
done
This will ...
4
votes
4answers
458 views
How can I pass a command line argument into a shell script?
I know that shell scripts just run commands as if they were executed in at the command prompt. I'd like to be able to run shell scripts as if they were functions... That is, taking an input value or ...
4
votes
8answers
1k views
Can shell variable include - character?
I am not able to use - in variables in shell. Is there a way to be able to use it, because I have one script which depends on such named variables:
$export a-b=c
-bash: export: `a-b=c': not a valid ...
4
votes
4answers
108 views
Can I write the output the of time difference command to a file?
Can I write the output of the time difference command to a file?
For example, I tried:
$ time foo.sh > bar.txt
But it only gives the output of foo.sh to bar.txt.
4
votes
4answers
825 views
Building paths robustly
Say I have several variables in a shell script (e.g. in zsh):
FOLDER_1, FOLDER_2, etc.
These variables refer to folders descending from /. For example, if I have a path /home/me/stuff/items
the ...
4
votes
5answers
114 views
How to use ' in alias?
I have one-line that I want to call using alias.
while printf '%s ' "$(df -P / | awk 'NR==2 { print $(NF-1) }')"; do sleep 30; done
I tried to escape ' like \' but it didn't work.
What is the ...
4
votes
2answers
198 views
Combine two commands in .bash_profile
In my .bash_profile file, I'd like to setup a single command alias that is two commands that execute one after another. The first command takes an argument from the command line and the second is ...
4
votes
3answers
13k views
How can I concatenate a shell variable to other other parameters in my command lines?
How can I concatenate a shell variable to other other parameters in my command lines ?
For example,
#!/bin/sh
WEBSITE="danydiop"
/usr/bin/mysqldump --opt -u root --ppassword $WEBSITE > ...
4
votes
4answers
102 views
sed how to substitute when string has “http://” in it?
I have a file xx that has the following contents:
@base_url = "http://dmstaffing-stage.herokuapp.com/"
I want to use sed to eliminate this line (replace with nothing). I have used this sed ...
4
votes
3answers
1k views
Get lines with maximum values in the column using awk, uniq and sort
I have a file with next format
2011-12-01 user1 access1
2011-12-01 user1 access2
2011-12-01 user2 access2
2011-12-01 user4 access2
2011-12-02 user1 access1
2012-01-01 user3 access1
2012-01-01 user4 ...
4
votes
2answers
381 views
How to output file & ignoring lines that start with “?”?
I do svn status --show-updates and then I want to either
Q1:
ignore (not to display) lines that start with ?
Q2:
display only lines that start with * Note that there are few spaces before * occurs. ...
4
votes
2answers
314 views
How to list files and directories with directories first
I have two questions. First, which command lists files and directories, but lists directories first?
Second question: I want to copy a list of files into a single directory, but make the target ...
4
votes
2answers
1k views
How to pipe md5 hash result in shell
I am looking for a simple way to pipe the result of md5sum into another command. Something like this:
$echo -n 'test' | md5sum | ...
My problem is that md5sum outputs not only the hash of the ...
4
votes
2answers
2k views
How do I give all the permissions to a file for a single user that's not me?
When I want to grant access to another user to my file, I use chmod 777 file, but if I want to be sure I'm granting permission just for that user, how can I do it?
-- update
The file is owned by ...
4
votes
5answers
253 views
Execute string result from shell script as a set of shell commands
I create a string result from my shell script and i want to execute it as a shell command.
For example file_a is:
user1@gmail.com
user2@gmail.com
script:
awk '{print "mail -s \"welcome\"", $1}' ...
4
votes
3answers
3k views
File extensions for unix shell scripts
On wikipedia, the article for .sh says:
For the .sh file extension type, see Bourne shell.
How about other unix shells?
I know that the shebang is used inside the file to indicate an ...
4
votes
2answers
1k views
4
votes
2answers
278 views
Simple “Variable” Bash File
So I just want to make a simple bash file, that takes a file name as a parameter. In that bash file, I want to take the name, before the extension, and have it as a "variable", to use in other places. ...
4
votes
3answers
72 views
Why is sed giving me an error about an unterminated `s'?
I have a set of sed replacements in a bash script and am getting an error about an unterminated `s' command. Here's what the sed line looks like:
sed -n -e "s/TMPFOO1/$FOO1/" -e "s/TMPFOO2/$FOO2/" ...
4
votes
4answers
65 views
linux + how to ignore (filter) file with space
Sometimes a file name is created from a couple of names and space between each name as the following:
$ touch "A B C"
$ ls
A B C <-- one file but has three words ! ...
4
votes
4answers
250 views
Count lines matching pattern and matching previous line
I want to count the number of times that a role is successfully deleted. The problem is that one line of the log file will show that the script is about to delete the role:
Prepare to remove role X
...
4
votes
3answers
261 views
Find files that have words in common
What would be the best way to create a list of files that have common words with a given file. For example, if I had:
$ ls
mainFile file1 file2 file file4
$ cat mainFile
exquisite malicious ...
4
votes
1answer
429 views
How is this sed command working?
I want to understand, how following sed command is working:
sed -nre "/jar$/ { x; d; }; /class$/ { x; p; }
Actually it is part of another command to find a particular class file from the given list ...
4
votes
1answer
2k views
shell backup script, missing `]`
I'm putting together a simple backup script that will tar contents of a folder, then move that file to a backup server. The script makes sure that the tar file exists and is not zero bytes before ...
4
votes
6answers
2k views
How can I convert tab delimited data to comma delimited data?
I'm requesting a list of ec2 snapshots via amazon's ec2 command line tool:
ec2-describe-snapshots -H --hide-tags > snapshots.csv
The data looks something like this:
SnapshotId VolumeId ...
4
votes
4answers
592 views
How to get the network status (online/offline) and attribute it to a variable in shell script?
How to get the network status (online/offline) and attribute it to a variable in shell script?
4
votes
3answers
240 views
Is there a way to call a command with a set time limit and kill it when that time passes? [duplicate]
Possible Duplicate:
Run a command for a specified time and then abort if time exceeds
I was working on a continuos integration build script when a need for such a command arose. Basically ...
4
votes
1answer
686 views
How to find out common elements between two files?
For an example, I have 2 files having following info:
File #1:
12
13
14
15
File #2:
12 1
13 2
14 2
15 6
16 7
17 8
Output File:
1
2
2
6
In the output file, I want only the second column ...
4
votes
3answers
292 views
How to poll existence of a background script correctly
I have a problem with the following kind of script:
#!/bin/sh
long_running_script.sh &
while [ `pidof long_running_script.sh` ]
do
echo "."
sleep 1
done
The sript will ...
4
votes
2answers
1k views
How to configure mailx to support Gmail?
How can I set up mailx to send messages to my Gmail account? What I do now is run the command:
mail -s "hello kid" mymail@gmail.com
It freezes and does nothing. I tried some variations, but all of ...
4
votes
2answers
2k views
Set Variable Environment Variables in bash (or other)
I want my script to read a file containing key/value pairs of environment variables to set, and then to set them.
So far, I have this:
#!/bin/bash
cat $1 | while read kv
do
key=${kv%=*}
...
4
votes
3answers
2k views
Why the double quotes and backquotes in a shell script?
I'm looking at this script mysql backup script and I don't understand what is the reason for using both backticks and double quotes around command names?
379 WHICH="`which which`"
380 AWK="`${WHICH} ...
4
votes
3answers
3k views
Simple Shell Script with Arithmetic issue… ** is giving me trouble
When I run this script I get this error:
./myscript.sh: 16: arithmetic expression: expecting primary: "1 ** 1"
When I run this shell script with bash, as in #! /bin/bash on the first line, the ...
4
votes
3answers
762 views
renaming files without the **rename** command
I have a directory of files,
Measurements Panama 2009-03-22 Session1.xml
Measurements Panama 2009-03-22 Session2.xml
Measurements Panama 2009-03-22 Session3.xml
Measurements Panama 2009-03-22 ...
4
votes
4answers
670 views
Text between two tags
I wanna retrieve whatever is between these two tags – <tr> </tr> – from an html doc.
Now I don't have any specific html requirements that would warrant for an html parser. I just plain ...
4
votes
1answer
464 views
“unexpected end of file” in bash script
I have this if in a bash script:
if [ $ACTION = deploy ]; then
${JAVA_HOME}/bin/java ${JVM_ARGS} weblogic.WLST << EOJ
connect('XXX','XXX','t3://XXX:8001')
jndi();
ls();
...
4
votes
3answers
1k views
How to get subshell's PID in Korn Shell (equivalent of $BASHPID)
In bash you have this handy variable: $BASHPID wich always returns the currently running subshell's PID. How can I get a subshell's PID in ksh? For example see the code below:
#!/usr/bin/ksh93
echo ...
4
votes
2answers
275 views
Can I trace a dash script without modifying its source code?
I would like to trace a shell script for debugging purposes without having to modify its source code (e.g. change the shebang or insert a set -x at the beginning). It is a dpkg postinst script, so not ...
4
votes
4answers
380 views
Is there any book , Tutorial on very very advanced shell scripting
I am looking for some tutorial where a simple script is written using very advanced methods so that i can learn more from
4
votes
1answer
742 views
Bash script IDE
Is there a bash/ksh/any shell script IDE.
Don't you get annoyed when you forget the space inside if or I don't know, some minor syntax mistakes you do from time to time, but takes you a long time to ...
