A shell script is a script written for the shell, or command line interpreter, of an operating system.
0
votes
1answer
68 views
Why does my TCSH prompt change after cd?
My .cshrc file contains the following:
set prompt = "%{\033[0;32m%}%S%B\! <%~> :%b%s %{\033[0m%}"
Each time I cd out of my home directory, the prompt formatting resets to display:
33 ...
0
votes
1answer
59 views
How given script makes executables in /usr/local/bin/
While doing project , I found a script that is bounced over my head. Can you help me to understand this script . Please explain this script step by step.
SCRIPT
if ! [ -f /usr/local/bin/XXX -a -f ...
6
votes
3answers
244 views
What's the difference between Ctrl-Z and kill -STOP?
When I run a command (make on a large project) from the shell, I can type Ctrl-Z to stop the process and return to the shell. Subsequently, I can run fg to continue the process.
I'm trying to write a ...
1
vote
0answers
79 views
how to create a script to backup MySQL databases on separate files?
I need to create a script so to automate the backup process for my database server. Today there are 19 databases on the server and to prevent some schema is created and not contemplated by the script, ...
1
vote
3answers
72 views
Get separate used memory info from free -m comand
As a output of free -m command I got following.
total used free shared buffers cached
Mem: 2496 2260 236 0 5 438
-/+ ...
3
votes
2answers
129 views
Simple Shell script to log disk space
I'm working on automating collecting disk space on a group of servers.
In a standard terminal, if I run:
ssh server1 ssh server2 df -h
Then I get the output of the command, just fine.
...
2
votes
2answers
102 views
Testing a string containing only spaces (tabs, or “ ”)?
My code below doesn't work:
stringZ=" "
if [[ "$stringZ" == ^[[:blank:]][[:blank:]]*$ ]];then
echo string is blank
else
echo string is not blank
fi
Result:
string is not blank # wrong
...
1
vote
3answers
160 views
How to get data count between two strings with multiple occurences in the same file
I have the data in my file as
START-OF-FIELDS
ID
NAME
DEPT
END-OF-FIELDS
START-OF-DATA
1|joy|cs
2|sam|ec
END-OF-DATA
START-OF-FIELDS
ID
NAME
DOB
DEPT
ADDRESS
END-OF-FIELDS
START-OF-DATA
...
3
votes
1answer
98 views
How can I remove an element from an array completely?
unset array[0] removes the element but still if I do echo ${array[0]} I get a null value moreover there are other ways of doing this but if an element of an array contains spaces like below
...
3
votes
4answers
103 views
Replacing pattern after nth match is found on each line?
I have a file containing lines:
india;austria;japan;chile
china;US;nigeria;mexico;russia
I want to replace all the occurences of semicolon on each line with e.g. ;NEW;, but starting from the 2nd ...
3
votes
4answers
221 views
Avoiding busy waiting in bash, without the sleep command
I know I can wait on a condition to become true in bash by doing:
while true; do
test_condition && break
sleep 1
done
But it creates 1 sub-process at each iteration (sleep). I could ...
0
votes
2answers
67 views
perl one liner + print VALUE in the end of the line
The following perl one liner checks if $CURRENT_VERSION matches $NEW_VERSION exactly, and prints it if it does.
Example:
CURRENT_VERSION=223.3.12.4.5.3
NEW_VERSION=223.3.12.4.5.3
DATE=17.3.2013
...
0
votes
2answers
144 views
Xdotool using “DISPLAY=:0” not works in Crontab
I need to run shell script contains Xdotool codes in /home/z/Desktop/tempo/run.sh. I've tried many ways of DISPLAY=:0 but always not works.
I've tried each of below codes, and not works:
* * * * * ...
3
votes
1answer
96 views
Searching for Failed attemps in /var/log/secure
I'm currently writing a script to examine /var/log/secure file and report how many failed attempts there were that day. I need to output it in the following format:
Date: 03/15/10 Time: 10:30 Number ...
2
votes
1answer
72 views
Script to send mail if there has been no entry in a log file for a certain amount of time
I am new to shell scripting. How would I write a script which can send an alert mail if there is no entry in the log file for more than 3 hours.
2
votes
4answers
173 views
Using the not equal operator for string comparison
if [ "$PHONE_TYPE" != "NORTEL" ] || [ "$PHONE_TYPE" != "NEC" ] || [ "$PHONE_TYPE" != "CISCO" ]
then
echo "Phone type must be nortel,cisco or nec"
exit
fi
The above code did not work for me, so I ...
1
vote
0answers
102 views
rc.local not being executed when os boots up
I have a script that needs to be run when os boots up. I added it to /etc/rc.local. It was working fine for sometime but now rc.local does not load at boot time.
When i checked the permissions on the ...
0
votes
1answer
57 views
top not working
My below cronjob is not working. What am I doing wrong here??
*/5 * * * * /usr/bin/top -n1 | head -10 >>/tmp/load.txt
1
vote
2answers
44 views
Turning standard output hyphen into a single command
I am working with scripts that output xml and I am using xmllint to format the output. Xmllint requires a source argument, so I use the hyphen to pipe standard output to it:
$> script.php ...
2
votes
1answer
79 views
perl + combine exec command with perl one liner line
I have the following short perl script rename.pl. How can I translate this script to one liner perl syntax? And how to combine the perl one liner in find command?
rename.pl
#!/usr/bin/perl
$op = ...
0
votes
0answers
48 views
how to parse this data and count the matching patterns? [closed]
Gi1/0/12
Gi1/0/13
Gi1/0/14
Gi1/0/15
Gi1/0/16
Gi1/0/17
Gi1/0/18
Gi1/0/19
Gi1/0/20
Gi1/0/21
Gi1/0/22
Gi1/0/23
Fa2/0/13
Fa2/0/14
Fa2/0/15
Fa2/0/16
Fa2/0/17
Fa2/0/18
Fa2/0/19
Fa2/0/20
Fa2/0/21
Fa2/0/22
...
1
vote
1answer
73 views
How to parse this output and put it into an array?
i have expect script whose output looks like :
I would like to extract all words like Gi/02/12 etc in an array or a list.
VLAN Name Status Ports
---- ...
1
vote
1answer
89 views
How to safely put user typed password into a file?
Is there any way to put the password typed by user into a file (either in Unix or in expect).
read -s -p "enter password" input
echo $input > file
Is the above code safe?
I want to use that ...
1
vote
2answers
177 views
multiple background processes in a script
Suppose if i have a situation in which some files need to be copied and it takes long time so
i would have to go for parallel processing of the file copy.
for example it may look like this
for i in ...
4
votes
4answers
252 views
Count lines matching pattern and matching previous line
I want to count the number of times that a role is successfully deleted. The problem is that one line of the log file will show that the script is about to delete the role:
Prepare to remove role X
...
1
vote
2answers
77 views
renaming a directory and its subdirs without affecting their files
I have to rename directories under the root directory with prefix "ms_PF" and then rename their subdirectories with the modified name of the main directory with an extra "_", and then copy all ...
2
votes
2answers
91 views
How do I use an If-Else query based on the day of the week?
Problem: I need to check if today is Thursday and perform different actions based on the result of this condition. I tried two different approaches:
Getting the Day Name:
DAYOFWEEK=$(date +"%a")
...
5
votes
2answers
86 views
[ vs [[ : which one to use in bash scripts? [duplicate]
The zsh man page, in its section on test (aka [), explicitly advises against using it at all, and urges readers to use [[ whenever possible.
The relevant section states:
The command attempts to ...
3
votes
2answers
88 views
Concatenate block of lines with following block of lines
I am trying to process some text exported from lecture slides using pdf2text. The bullet points of some slides show up like this:
title for the list
-
-
-
a bullet point text
another bullet point ...
2
votes
3answers
603 views
Bash script; optimization of processing speed
I was wondering if there are general guidelines for optimizing bash script.
a) For example, it is more convenient to write loops than lines of commands, but is it also faster to process for the ...
2
votes
3answers
95 views
Linux command line that will fail if any standard out is produced
Is there a simple utility which I can pipe output to on Linux that will:
Return a success code if there is no output on standard out (and / or standard error).
Return a failure code if output is ...
8
votes
3answers
357 views
How can one run multiple programs in the background with single command?
How can one run multiple programs in the background with single command?
I have tried the commands below, but they do not work.
nohup ./script1.sh & && nohup ./script2.sh &
-bash: ...
2
votes
1answer
66 views
Difference between two types of shell arithmetic
What is the difference between the following two shell arithmetic commands:
echo $[ $var1 - 1 ]
echo $(( $var1 - 1 ))
Assuming var1 = 5 for example.
2
votes
2answers
188 views
What's the best way to backup files via network on Linux and Solaris machines?
I wonder what the best way to backup files VIA network
I have Solaris machines with Oracle 10i with VERITAS cluster, machines are connected to EMC storage
/data/oracle directory is mounted on the ...
2
votes
1answer
210 views
Users home path in a bash script
I'm writing a bash-script that will be run as a cron job everyday. Very basic, I was wanting to change the wallpaper daily. I have mint-14 with mate.
The thing I'm getting caught up on right now ...
-1
votes
2answers
278 views
Bash -Extract characters from string
Suppose I have the following variable
$string = 'cat somecommandhere'
Now the output of the above cat command is
test="Thanks serverfault"
I want to extract the value between the quotes and ...
2
votes
1answer
244 views
error handling in expect?
I am just improving my quetion becasue i have acieved so far upto this:
set username [lindex $argv 0]
set password [lindex $argv 1]
set hostname [lindex $argv 2]
if {[llength $argv] == 0} {
...
2
votes
1answer
245 views
Create sub-directories and organize files by date
I have some directories of files copied from my security camera that I would like to organize into sub-directories by file date. So for example;
-rwxrwxrwx 0 root root 4935241 Jul 19 2012 ...
2
votes
2answers
96 views
How to pass the output of a script to a command like ls without the output being split?
Suppose I have a script like this:
#!/bin/bash
printf '%q\n' "b c"
Executing the script prints:
b\ c
on the commandline.
Now, being in a directory which contains a file named b c I want to pass ...
1
vote
1answer
164 views
Is there some sort of “no newline at eof” rules for bash scripts?
I have two files, an env file and a run file. When I deploy them to my Ubuntu Server box I get the error:
./start-admin: line 10: syntax error: unexpected end of file
If I deploy and then add a ...
2
votes
1answer
49 views
how do i suppress seds unnessary output while using option -e?
why n option is not working here
[root@testgfs2 final]# echo a b c | sed -ne 's/[[:blank:]]/"/gp' -ne 's/^/"/pg' -ne 's/$/"/pg'
a"b"c
"a"b"c
"a"b"c"
i just need :
"a"b"c"
actually ...
2
votes
2answers
101 views
changing pattern by removing spaces?
file :
hi hello,new york, , ,brazil site ,brazil
january,month is feb , , ,indiana jones
task:
delete all horizontal space (spaces and tab) between any two comas (like , ,) if ...
0
votes
1answer
36 views
Package Installation log creation
I have written a script for installing packages on Linux(Ubuntu). So I want to create a log file for installation of packages for troubleshooting if any problem occur during installation.So please ...
1
vote
1answer
107 views
How to ssh on multiple ipaddress and get the output and error on the local *nix machine?
command="ls -lrt;uname -a;uname -o"
for i in 10.38.227.229 10.38.164.103
do
ssh auto21@$i "$command 2>&1" >> log
#ssh -n auto21@$i "$command" 2> >> log
done
i am trying ...
3
votes
1answer
359 views
SSH causes while loop to stop
I have finally managed to boil down a problem I have been struggling with for a few weeks. I use SSH with "authorized keys" to run commands remotely. All is fine except when I do it in a while loop. ...
0
votes
1answer
74 views
Moving Same files from different folders using shell script on AIX 5.4
There are two folders named Folder1 and Folder2.
Folder1 has files with name:For example
S-080001-0-0.xml with its corresponding same files in Folder2 named S-080001-0-0.xml
The change in Folder2 is ...
5
votes
2answers
204 views
Find all files with a Python Shebang
I'm trying to run a PEP8 check against a large source tree. The tree is comprised of a mix of files in various languages. The idea is to check all the Python scripts without having to explicitly list ...
2
votes
1answer
125 views
shell variable in awk is not being passed to all the lines but just for the very first line of input?
inputfile:is2.txt
10.39.5.41,A1,B1
10.39.5.41,A2,B2
10.39.5.41,A3,B3
10.39.5.41,A4,B4
10.39.5.41,A5,B5
10.39.5.41,A6,B6
script :
#!/bin/bash
second_column="OOOOOOO" # OOOOOOO will be added to ...
1
vote
1answer
95 views
reading from a file and changing its pattern into an array?
I have a CSV file containging entries like this :
ipaddress,VLAN,VLANid
10.192.168.1,vlan-xyz,3
10.192.168.1,vlan-abc,8
10.192.168.1,vlan-mnp,11
10.192.163.24,vlan-llz,3
10.192.163.24,vlan-bbz,5
...
1
vote
2answers
237 views
Print given number in reverse order
clear
echo "Enter a number"
read n
sd=0
rev=0
while [ $n -gt 0 ]
do
sd=$(( $n % 10 ))
rev=$(( $rev *\ 10 + $sd ))
n=$(( $n / 10 ))
done
echo "Reverse number of entered digit is $rev"
...
