Bash is the Bourne Again SHell, the successor to the classic Unix sh (shell).

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2
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1answer
870 views

Calculate average of every 5 samples with rrdtool or other languages

I want to make an average of 5 samples and calculate a single value: Current output - I put resolution of 5 minutes but receive 5 samples: $ rrdtool fetch file.rrd AVERAGE -r 300 --start 1200000000 ...
241
votes
11answers
289k views

How to determine if a bash variable is empty?

What is the best way to determine if a variable in bash contains ""? I have heard it recommended that I do if [ "x$variable" = "x" ] Is that the correct way? (there must be something more ...
4
votes
1answer
2k views

Using a shell script to check if rsync made any changes

I've got a bash script that rsync's two directories. Sometimes there's a change, odds are there's nothing. I want to run a command only if rsync actually made a change (add/update a file). ...
1
vote
1answer
47 views

How to make a simple script that increases a number character by 1

I have to add a single command for MANY vlans, and wondering if I can generate a simple text file somehow? Then I can simply paste the text file into the network switch and it will add the needed ...
8
votes
2answers
9k views

Writing to stdin of background process

I'm on an Ubuntu 10.04 box, and started a server in the background (myserver &) over ssh. It's been running fine, but I need a way to get at the server's stdin, as the only way to control the ...
1
vote
1answer
38 views

How can I know the absolute path of a running process? on solaris

this is the command to view the process path on Linux ps -auxwe | grep 24466 ( 24466 is only example ) but please advice is it possible to view the path of running process on Solaris if yes ...
0
votes
1answer
887 views

JBoss EAP 6.2 on RHEL 6: ./bin/init.d/jboss-as-standalone.sh hangs while calling via SSH

I'm using jboss-as-standalone.sh to manage JBoss EAP standalone as a service. I can start/stop the service with "service jboss-as-standalone.sh start/stop" while I'm on a terminal. But I would like ...
0
votes
1answer
19 views

Should I be adding aliases to /etc/profile instead of /etc/basrhc?

I've been adding them to /etc/basrhc, and that works most of the time. But I noticed that when I su to another user, I lose all my aliases. It turns out that /etc/bashrc is only loaded when the ...
4
votes
1answer
1k views

Standard place for user defined bash_completion.d scripts?

I have user access (no root) into a Linux (Suse) machine where I developed some bash scripts and the corresponding bash autocompletion rules. Since the scripts belong only to my user and therefore I ...
6
votes
4answers
7k views

How to parse and convert ini file into bash array variables?

I'm trying to convert an ini file into bash array variables. The sample ini is as below: [foobar] session=foo path=/some/path [barfoo] session=bar path=/some/path so these become: ...
0
votes
1answer
18 views

Resolve packages not found and errors during configure,make,make install in a script

I need to have a script that will install a package from source in a Linux system and need to know how to take care of the errors that usually come up as a result of the first step ./configure maybe a ...
19
votes
8answers
7k views

Is there any reason to use bash over zsh? [closed]

I'm curious about why one would want to run bash instead of zsh. I mean zsh is fully backwards-compatible with bash. Don't get me wrong: I don't dislike bash or anything. I just genuinely want to ...
2
votes
2answers
252 views

Why doesn't this command work as a cronjob, while it works perfectly when typed in a shell? [closed]

If I run this command from the shell, it works as expected: cd ~ && mysqldump --databases --skip-dump-date --host=localhost --user=admin --password=xxxxx --lock-all-tables ...
0
votes
1answer
37 views

Issue with Bash Script On FreeBSD

I have the below bash script set to run every hour via cron as the root user. The purpose of this script is to email us when files have been uploaded to our sftp server and send us the logins. Here is ...
20
votes
6answers
8k views

Can't log in via SSH to any accounts set to use /bin/bash as a default shell

I'm trying to install bash as the default shell on a ARM Linux running on an embedded device (Synology DS212+ NAS). But there's something really wrong, and I can't figure out what it is. Symptoms: ...
0
votes
1answer
53 views

How to automate input for a repetitive script! Expect in Bash?

I am a junior sys admin. Reason I'm asking this question is because we don't have a senior sys-admin here who is proficient with scripting. Senior guys are at the head office and too busy for ...
0
votes
1answer
1k views

Improper output in SSH session on OSX using FreeSSHd on Windows with cygwin bash/sh shell

I am testing out running an SSH server on a local Windows VM. I have installed FreeSSHd and set the command shell to "c:\cygwin\bin\sh --login -i" (bash as well) with "Use new console engine" ...
0
votes
1answer
51 views

Bash: Output of a command is written only to screen and not to another file while using tee, what could be the reason?

In order to troubleshoot some ftp connection error, I've been instructed to write a bash script which will infinitely connect to a remote frp server and get one file from there. ftpuser="ftpuser" ...
1
vote
1answer
899 views

Problems in monitoring file age with nagios (command substitution in filename)

In my current nagios installation I check for the existence of a remote backup through NRPE. In particular, my remote nrpe.cfg (on a Ubuntu 8.x) is: ...
1
vote
4answers
2k views

Running ssh-agent from a shell script

I'm trying to create a shell script that, among other things, starts up ssh-agent and adds a private key to the agent. Example: #!/bin/bash # ... ssh-agent $SHELL ssh-add /path/to/key # ... The ...
7
votes
4answers
12k views

kill a screen (but not all screens)

I have multiple screens running on an Ubuntu server that are initiated as: screen -dmS screen1 cmd screen -dmS screen2 cmd etc... And I need to kill one screen, but not all of them. What is the ...
10
votes
2answers
9k views

How do ulimit -n and /proc/sys/fs/file-max differ?

I notice that on a new CentOS image that I just booted up off of EC2 that the ulimit default is 1024 open files, but /proc/sys/fs/file-max is set at 761,408 and I'm wondering how these two limits work ...
1
vote
2answers
62 views

Locally deny login to users authenticated via LDAP

I have a RedHat Linux server that are is use for more than 1000 users Users names are coming to the server via LDAP protocol, so login authentication is from the LDAP My question: is it possible to ...
1
vote
0answers
28 views

Git Pull on CGI and Command Line have different results

I have an "after push" webhook on GitHub that calls a CGI script to update a Jekyll website. The script: user@server [~/_repo]# cat cgi-bin/githook.cgi #!/bin/bash echo Content-type: text/plain echo ...
2
votes
0answers
25 views

Linux: What could be the reason for random fails in updating passwd.byuid by running yppasswd?

In order to allow NOC users in my company to manage users through NIS I've created the following script: #!/bin/bash # This script will simplicate NIS user management. # You will not be able to ...
2
votes
1answer
33 views

Linux: How can I get a different exit code from the find command if no files matching the pattern I used are found? [duplicate]

I have a script which runs the next command: find /storage2/hpfiles_staging/ -name \*.gz -mmin +600 And then rsync's the files to a remote location. Sometimes the find command returns no output ...
0
votes
1answer
27 views

issue with xinetd arguments

i have created this BASH script called blah which does something simple like this (See below) #./blah -x "bindas" hello bindas i would like to execute script using xinetd with dynamic variable, ...
0
votes
0answers
16 views

Init script only offers help suggestion

I modified the uwsgi init.d script for debian from the apt-get package download. This is the script I have below: #!/bin/sh ### BEGIN INIT INFO # Provides: uwsgi # Required-Start: ...
4
votes
5answers
4k 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 ...
0
votes
0answers
33 views

How to package shell script file with license key file

I am working on automated shell script for specific task . Before executing task steps I want to validate the license key provided to the customer with a webservice call. Please help me in making ...
0
votes
4answers
2k views

grep and tabs: no match

#cat sample 1 -1 2 2 2 2 2 1-1 3 I need to get all the lines that contains negative value, that is 1st line only. Values are tab-separated. First I tried # grep "\-1" sample 1 -1 2 2 ...
3
votes
2answers
291 views

How to prevent GNU screen from expanding tabs into spaces?

Using a normal bash prompt echo -e 'hello\tworld' produces a real tab. However the same command run within GNU screen puts spaces between the two words. I have tested this on Ubuntu 10.04 with Screen ...
6
votes
3answers
5k views

Find out which partition a directory is located on in Linux?

Is there a way to find out which partition a directory is located in? I know I can use df to list partitions and mount points but I need to be able to find out which partition any directory is ...
1
vote
3answers
897 views

I can run a script locally, but cannot do “ssh HOSTNAME /path/to/script.sh”

I have a linux server, and a linux desktop. I have written the following simple script to dump the database of a django web application: #! /bin/bash set -o errexit cd $(dirname $0) . ...
6
votes
2answers
4k views

Add server to known_hosts

I would like to add github.com to the known_hosts file from the command line as I am creating a puppet manifest to provision a remote server. I have tried: "ssh-keyscan -H github.com > ...
3
votes
2answers
214 views

Writing an SVN hook that updates copy of committed code

I have a SVN repository with a lot of sub-projects stored in it. Right now in my post-commit I just loop through all possible folders on the machine and run svn update on each: REPOS="$1" REV="$2" ...
1
vote
0answers
124 views

Powershell execute Queries using SQLPLUS

I have a RHEL server with Oracle 10G installed. I need to write a powershell script to query my database and get the output. I have imported Posh-SSH module and am able to connect to my RHEL server ...
0
votes
1answer
54 views

How to use environment variable in haproxy?

I work with haproxy 1.5.2 My haproxy.cfg has this server definitions: server HALB_ucd1 ${UCD1_END_POINT_IP}:${UCD1_END_POINT_PORT} check port 8444 I set the UCD1_END_POINT_IP and ...
3
votes
1answer
183 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 ...
2
votes
1answer
2k views

How to set a timeout within a BASH script for a process that sometimes becomes inactive?

I have a bash script that runs a lot of commands/tools like convert or pdftk via CRON. It happens quite often that e.g. pdftk becomes "stale" or "hangs" and the calling script stops proceeding. Is ...
12
votes
4answers
18k views

Multi-select menu in bash script

I'm a bash newbie but I would like to create a script in which I'd like to allow the user to select multiple options from a list of options. Essentially what I would like is something similar to the ...
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. ...
-1
votes
2answers
65 views

set bash alias from bash script (not command line)

Differently from bash shell (for create new alias): alias test="echo test" if I do the same thing using a bash script, alias does not run: #!/bin/bash alias test="echo test" also export it, same ...
18
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 ...
0
votes
1answer
45 views

catch bash script output from expect, expect hangs

I currently use expect to pass password to rsync to copy files across unix servers test.sh ./expect.sh $password rsync -azvr $username@$host:$file ./$dir expect.sh #!/usr/bin/expect -f ...
6
votes
2answers
5k views

cat * | grep something… what file is the result in?

If one was to run the following command cat * | grep DATABASE the shell would spit out all the lines in * files that contained the word DATABASE in them. Is there any way to also spit out what file ...
0
votes
2answers
388 views

Strip out the 'n' \ new line out of the echo to a file [closed]

I have a bash script that pulls a bit of text from an external MySQL database. Most of the times it are 4 lines, each one on his own line. This text (in total) has to be placed into a file. The script ...
2
votes
2answers
58 views

Manipulate JSON in bash

I have a JSON file I need to update a particular value. { "Comment": "comment", "test": { "enabled": true }, "enabled": true, "otherStuff": blah, "otherStuff2": blah, "otherStuff3": ...
0
votes
1answer
48 views

Command fails during script execution in bash

I'm working on a bash script for automatize some common tasks but I'm having some issues and I need some help. This is the script I'm talking about: #!/usr/bin/env bash PS3='Please enter your ...
0
votes
0answers
41 views

CentOS - how to chroot sftp and have mysql as shell

I have a user who I would like to have sftp access to one folder only (chrooted). Also he logs in with ssh, I would like him to only have access to mysql. I am able to chroot the users sftp (by ...