Programming in an Interpreted language executed by a running Shell

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21
votes
5answers
62k views

How do I sleep for a millisecond in bash or ksh

sleep is a very popular command and we can start sleep from 1 second: # wait one second please sleep 1 but what the alternative if I need to wait only 0.1 second or between 0.1 to 1 second ? ...
19
votes
1answer
2k views

Ctrl-C in bash scripts

How do I implement ctrl+c handling in bash scripts so that the script is interrupted, as well as the currently running command launched by the script? (Imagine there's a script that executes some ...
18
votes
1answer
1k views

Shell command slow when using pipe, fast with intermediate file

Does anyone understand this huge difference in processing time, when using an intermediate file, or when using a pipe? I'm converting tiff to pdf using standard tools on a fresh debian squeeze server. ...
11
votes
4answers
2k views

Can a shell script wait for a file to change and take action?

I wonder if I can write a script that will monitor for a change in a file and execute some action when the change is detected. Detailed explanation: OpenVPN writes its status to a file every 1 ...
7
votes
2answers
3k views

How to grant sudo rights only to specific script files?

I would like a user to have sudo rights (without password check) to a couple of shell scripts under a specific directory (in my case, /usr/local/tomcat7/bin), and to nowhere else. What's the simplest ...
7
votes
1answer
1k views

using temporary files vs pipes advantages and disadvantages

Say I have a file named jobs.csv and I would like to get the top 50k jobs done by Foo I can either do: # cat jobs.csv | sort -u | head -n 50000 > /tmp/jobs.csv # cat /tmp/jobs.csv | while read ...
6
votes
1answer
214 views

identifying ssh trusts between multiple servers on a network

The problem: We have many dev/qa/prod RH/Solaris servers with many accounts having ssh trust between them, including between servers in different environments (prod->prod, but also qa->prod). I know ...
5
votes
5answers
5k views

Connect to MySQL trough command line without need root password

I'm building a Bash script for some tasks. One of those tasks is create a MySQL DB from within the same bash script. What I'm doing right now is creating two vars: one for store user name and the ...
5
votes
3answers
3k views

“watch” command to notify on newly created files on linux

watch command to notify on newly created files on linux How to modify the below command to notify on creating a new file to /usr/local/mydir/ by linux user john ? watch -d 'ls -l /usr/local/mydir/ | ...
5
votes
4answers
5k views

From a shell script, how can I check whether a table in MySQL database exists or not?

I am trying to write a script which allows a user to select the what manipulation he needs to do on a table. I want to check if the table exists or not. If it exists I will continue the other things ...
5
votes
1answer
342 views

perl equivalent of sh -e

In /bin/sh and /bin/bash (and I guess a lot of other shells), starting scripts with #!/bin/sh -e (or executing set -e in someplace in the script) would cause the script to abort when any command line ...
5
votes
3answers
132 views

Returning A List Of Quoted Files Paths Using Find

I would like to create a tarball that contains files from a directory that have a ctime of less than 30 days. Most tutorials I have found have basically recommended doing something like this: tar cvf ...
5
votes
2answers
4k views

ssh fails to execute remote command when run from cron bash script - works from CLI

I have a script, written in bash, which runs from cron. One of the first things it does is SSH to a remote host and retrieve a list of files in a directory. Everything works fine when run from the ...
4
votes
2answers
4k views

Unix separate multiple commands which has '&' (execute in background) in the end

To separate regular commands in Unix is to put semicolon in the end like this: cd /path/to/file;./someExecutable; But it seems not working for commands like this: ./myProgram1 > /dev/null & ...
4
votes
2answers
6k views

How to set postgresql user password in bash script

I want to set a password for the default Postgresql server user, postgres. I did it by using: sudo -u postgres psql # \password postgres I want to do this step in many machines, so I would like ...
4
votes
2answers
1k views

Access windows file system from linux shell script

I want to know, whether is it possible to access the Windows files from a shell script on Linux system ? What i am trying to do is to run a shell script in my Linux system, that will access the files ...
4
votes
2answers
2k views

Can I change the ownership of all the files of a specific user?

Is there a way to recursively find all files owned by a user and change them to another user/group in Gnu/Linux? I assume there must be some magic one liner but my command line wizardry skills are ...
4
votes
3answers
212 views

Detect fails in setup script

I wrote a setup script to install my prefered programs and settings after I got a new server. apt-get install git git clone http://me@myvimsetting.github.com .vim ln -s .vimrc .vim/vimrc ... But if ...
4
votes
1answer
499 views

Shell script: the child process do not terminate in linux

I have written a shell script to initiate three background process in the same time. In shell script I am trying to wait for all children to finish their job and then the parent job to terminate. But, ...
4
votes
2answers
3k views

expect script + expect miss the send string + delay issue

I write the active.ksh script (based on expect) in order to login automatically to some Solaris machine and execute the hostname command (login to virtual IP in order to verify which hostname is the ...
4
votes
2answers
823 views

Shell script: Find entries in access log with 500 response within a specified date period

Can someone help me with a shell script to figure out the number of 500 HTTP response entries in an access log within a time frame specified?
4
votes
2answers
5k views

Does mysqldump return a status?

I am creating a script that backups a mysql db using the mysqldump utility. I am writing this script in the shell "sh". I would like to capture the output status of mysqldump in the script (i.e. if ...
4
votes
3answers
1k views

Bash-Scripting - Munin Plugin don't work

i have written a munin-plugin to count the http-statuscodes of lighttpd. The script: #!/bin/bash ###################################### # Munin-Script: Lighttpd-Statuscodes # ...
4
votes
2answers
1k views

expect + how to identify if expect break because time out?

The target of the following simple expect script is to get the hostname name on the remote machine Sometimes expect script fail to perform ssh to $IP_ADDRESS ( because remote machine not active , etc ...
4
votes
1answer
52 views

Script does not run under Domain Administrator

Server running 2003R2. I have a script, which basically sets a variable, which then uses it to name a backup file. I have given the exact script here: echo > "%temp%\tmp.vbs" wscript.echo 10000 ...
3
votes
2answers
176 views

supress expansion of * in echo

I am working on a script which dynamically executes some queries on daily basis. These queries are coming from a table in the database. Here is the sample output of the query table: ...
3
votes
3answers
21k views

How to run a script automatically on system startup in centos

I've successfully installed TeamCity ib CentOS 6.2 Minimal. I'm stuck on trying to run a script automatically on system startup: /opt/TeamCity/bin/teamcity-server.sh start I've googled around and ...
3
votes
3answers
873 views

Year Month day from file name in shell script

I hava file names like below adn_DF9D_20140515_0001.log adn_DF9D_20140515_0002.log adn_DF9D_20140515_0003.log adn_DF9D_20140515_0004.log adn_DF9D_20140515_0005.log adn_DF9D_20140515_0006.log ...
3
votes
1answer
179 views

echo $? doesn't work when executed remotely

When I execute a command as below it gives me an output as expected but when I run the same command on remote server it always gives me echo $? as 0. locally # <some command> # echo $? ...
3
votes
1answer
335 views

How to schedule a Cron job for the second to the last day of each month

I want to schedule a task for the second to the last day of each month. I have read this great article about shell scripting the execution. I have also seen that you can use "L" to represent the last ...
3
votes
1answer
4k views

How can I replace line #6 in a text file in a bash script?

I have a text file that is generated by 3rd-party software as part of a build process. I want to replace one specific line - in my case, line 6. How can I do this in my bash script? I suspect sed is ...
3
votes
3answers
4k views

power shell error: Cannot bind parameter

when i am trying to execute the below PowerShell command, i got error . The command : *PS cert:\currentuser\authroot> gci | where subject -like "UTN"* The error is below : Where-Object : Cannot ...
3
votes
3answers
777 views

Email to run a bash script

I have a bash script to restart a service that runs every 3am to guarantee that the service isn't crashed when users require it. However, I need to provide a simpler way for my partner (that isn't ...
3
votes
2answers
2k views

Init script & the green [ OK ]

I am trying to install fast-cgi for nginx on an EC2 instance. I followed the steps explained here, but that is meant for Debian and does not work out of the box for a red-hat based system. I modified ...
3
votes
3answers
7k views

control a bash script with variables from an external file

I would like to control a bash script like this: #!/bin/sh USER1=_parsefromfile_ HOST1=_parsefromfile_ PW1=_parsefromfile_ USER2=_parsefromfile_ HOST2=_parsefromfile_ PW2=_parsefromfile_ imapsync \ ...
3
votes
1answer
188 views

shell script (KSH) + set file to param & perform test between param and string

in my linux machine red-hat 5.1 - in ppp file - I have only the signature.pl string !!! remark - third application write the signature.pl string in to ppp file I set ppp file in $a param And ...
3
votes
1answer
291 views

How to view two dialog boxes on the linux console, running on the same time?

I want to view on the Linux console two dialog windows on the same time. I want a window that views the progress BAR, and the a second tailbox that view the logs are running. The problem is that the ...
3
votes
4answers
541 views

Bash one-liner that shows a running countdown until a DNS update (TTL expiration)

I find myself frequently tasked with updating DNS records and needing to know exactly when the refresh will begin (a.k.a TTL expiration). I came up with this bash one-liner that gives me the output I ...
3
votes
2answers
3k views

How do you set a locale non-interactively on Debian/Ubuntu?

Usually, I run aptitude -y install locales then dpkg-reconfigure locales to set up locale. Now I want to put it into a shell script, how can I reliably do the following, automatically / ...
3
votes
1answer
4k views

Is it possible to set a timeout on openssl's s_client command?

I've got a script which uses openssl's s_client command to pull certificates for a big set of hosts. Some of these hosts will inevitably be unreachable because of a firewall. Is it possible to set ...
3
votes
1answer
627 views

How can I output the chkconfig results to a file within a shell script?

When I run the following from the linux command line it works properly and populates the chkconfig.bak file correctly : #chkconfig --list > chkconfig.bak But when the command is run from a ...
3
votes
2answers
267 views

Measuring “loading time in milliseconds” every minute

I have apache running on a virtual server, which in periods gives very bad performance - even when retrieving static JPG or PNG files. This only happens once in a while, so it's hard for me to ...
3
votes
3answers
515 views

How to pass command output as several arguments to another command

I have a command that produce a output like this: $./command1 word1 word2 word3 I want to pass this three words as arguments to another command like this: $ command2 word1 word2 word3 How to pass ...
2
votes
5answers
2k views

bash + print line every 10 min in bash

I want to print by echo the following "still in process wait another 10 min" every 10 min Please advice what condition needs to add before the echo command in order to print this line every 10 min? ...
2
votes
2answers
773 views

Date calculation in linux

In linux how to get the date of the first day of the week monday. I know that date +"%u" gives the current day of the week from this how to get the date of the monday of that week
2
votes
3answers
207 views

bash + how to match string that include characters and numbers

please advice - what's wrong with my syntax ? ( should not print the "bad interface " ) remark - I work with bash shell ETH_NAME=eth0 ( or any other as eth1 or eth2 .... ) echo $ETH_NAME ...
2
votes
2answers
4k views

Linux FTP upload: “No such file or directory”, but file exists

I want to upload backup archives from one server to another server using ftp. In my backup cronjob I use this script to upload files: MEDIAFILE=/var/somedir/somefile.encrypted if [ -r $MEDIAFILE ] # ...
2
votes
3answers
1k views

In zsh, how do you redirect stderr to /dev/null within a for or foreach loop?

I am trying to accomplish something that is easy in bash: look for files in a folder and source them if they exist (and do not output if no files exist). In bourne shells this is how to do it: if ...
2
votes
4answers
750 views

how to change permissions of specific file type

file * | grep 'ASCII text' | chmod -x chmod: missing operand Try `chmod --help' for more information. The above command gives me error.Basically I am trying to find all the files whose type is ...
2
votes
2answers
2k views

What is wrong? “Syntax error: unexpected end of file”

I keep getting this error, do you guys know what is wrong? rapache is an alias for restart apache mugbear:/usr/bin# cat /usr/bin/mkdomain if [ -d ...