Questions about shell scripts, executable files that are interpreted by a shell (bash, zsh, etc.).

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3answers
362 views

Executing bash shell scripts

I am reading an article on executing bash shell scripts. Method 1: Create a directory for your shell scripts and add the directory to the contents of the PATH variable, so that you can execute the ...
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3answers
332 views

Script to split string

@terdon's answer provides this script: find . -type f -name "*mp3" | while read file; do album="$(basename "$(dirname "$file")")"; filename="$(basename "$file")"; ...
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2answers
184 views

How can I tell what device or file name I am redirecting to

From within a shell script (sh/bash), how can I tell what device or file name I am redirecting to? For example, I have a shell script named script.sh. I run the shell script and redirect STDOUT to a ...
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4answers
111 views

How to get started with bash? [closed]

I need a way to be able to run a script that will automate terminal commands, one after another. As I understand it, this is exactly what bash does. (Am I right, even on this count?) Where can I ...
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2answers
514 views

How to invoke a shell built-in explicitly?

I want to customize the functionality of cd command as per my needs. I define following function - function cd () { cd "$@" && pushd "$@"; } The intent of this function is to automatically ...
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4answers
5k views

Match multiple regular expressions from a single file using awk

I'm trying to parse a HTML file using shell scripting. There are 4 different regular expressions that i need to catch: name= , age= , classs= , marks=. Using grep "name=\|age=\|class=\|marks=" ...
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1answer
264 views

How achieve variable indirection (refer to a variable whose name is stored in another variable) in tcsh

I'm trying to do the following: set a = kitten set temp_kitten = purr echo ${temp_$a} I want the echo command to return "purr". The overall idea is that I have a bunch of variables in an array and ...
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2answers
236 views

Remove complete line in text files based on Tags

For example : 01.txt, 02.txt, 03.txt and 04.txt has following values. HDR|A|B|C|D|F||||||| DTL|1|2|3|4|5||||||||||| DTL|5|6|7|8|9||||||||||| TLR|A|B|C|D|F||||||| I have to remove complete lines ...
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1answer
290 views

Udev: running a shellscript that accesses an X display [duplicate]

After getting my 3g-modem to work in Arch Linux I wanted to eliminate some manual labour required in the process. Hence I needed to create an udev rule. After some trial and error I came up with the ...
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0answers
482 views

Log in to multiple remote servers and execute a script [duplicate]

I want to make a script that will remote login to the multiple servers listed in a txt file like 10.3.9.6 10.3.9.7 and all servers have same username and password. and want to capture the output of ...
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2answers
100 views

How do i move a pieces of data between two words if the data has a % percent symbol at the begining?

I have a log file looking somtheing like : SWEs-elmPCI-A-01(config)# class AutoQoS-VoIP-RTP-Trust ^ % Invalid input detected at '^' marker. SWEs-elmPCI-A-01(config)# ...
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1answer
1k views

Reading the contents of the file and splitting using ksh

We're using a ksh script for installing one product. I've another config file, I'd need to read this configuration file from my main script Content of the Configuration file: ...
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2answers
14k views

Shell script to increment count of entries

I want a script which increments the count when the script runs. Basically I want to send an email notification when I find 10 devices down from the same country and scripts run after every down ...
1
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1answer
502 views

What is the canonical way to implement order independent options in bash scripts? [duplicate]

Possible Duplicate: How do I handle switches in a shell script? Most common shell commands allow the user to specify options in any random order. Positional Parameters like $1 as commonly ...
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5answers
3k views

Execute a command on multiple hosts, but only print command if it is successful?

Here's what I want to do. I want to check over 100 hosts and see if a file exists on that host. If the file does exist, then I want to print the hostname and the output of the command. In this ...
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3answers
454 views

Returning a portion of a line matching a pattern

I have a file (file_name) which contains exactly one occurrance of the string "Result: " at the start of a line. I want to print all the characters after the string "Result: " in that line until I ...
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1answer
50 views

parse first column of command output, get corresponding second column value

I am fairly new to BASH scripting for Linux. I am executing a command that outputs a table, as such: firstValue: a secondValue: b.y7 thirdValue: c-x-g 10:42 GMT Say I need the secondValue. I ...
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2answers
101 views

Regular expression for excluding data within a certain range

I want to remove all the IP addresses which are of the format 10.20.30.* and whose last 3 digits fall in the range 0 to 200 and move all the remaining IPs to a new file. I've put the IP list to be ...
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2answers
107 views

help with bash scripting tput getting errors [closed]

I am a beginner to bash scripting. I need help to figure out what is wrong with this tput menu. #!/bin/bash tput setb 3 tput clear function main_menu { option=0 until [ "$option" = "4" ]; do echo ...
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1answer
96 views

Ambigous redirect done >$2

I have finished my bash script but I am still getting two errors. I've also searched for related issues but none worked: #!/bin/bash avem_element () { local e for e in "${@:2}"; do [[ "$e" == ...
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0answers
40 views

Mount /var at boot runlevel 2 - problems

I'm working with a system that (for various reasons) often gets corruption on the /var partition. To this end I'm hoping to run e2fsck on it during the regular boot. I've commented out the /var ...
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0answers
332 views

Establish communication between Arduino Mega & Linux Terminal in Ubuntu 14.10

I am failing regularly in establishing syncing between my arduino mega(/dev/ttyACM0) and the terminal. Even I thought of establishing output using GNU Screen utility. The terminal just hangs for ...
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2answers
40 views

executing commands in shell and turnoff the default displays of commands in console [duplicate]

This is my script cd /opt/product/vinoth -- some operations -- cd - While executing this command cd - the old path get displayed in the console. is there is any way to block this from displaying ...
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1answer
134 views

Shell string escape for command arguments [duplicate]

I'm trying to create "/tmp/pwet/foo bar" with this: DIR="/tmp/pwet/foo bar" ARGS="-p ${DIR}" mkdir $ARGS For integration reasons, I have to keep the ARGS building in 2 steps: ARG = some_options + ...
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0answers
26 views

What does sort -n do with non numeric values? [duplicate]

I'm translating an old korne shell script that uses sort. The exact command is: sort -k 1.2,1.9n -k 1.10 -k 1.18,1.19 $LOAD_FILE > $SORTED_FILE The input file has some lines where the values in ...
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1answer
943 views

Init script to run a script as specific user

/apps/data/service/bin/startup.sh This is the script i want to be executed during RHEL booting. I want it to be run in runlevel 3 only. And i want this script to be started as specific user, ...
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3answers
478 views

Checking if line in file exist

I have a bash script which asks a user for the number of CPU cores and saves it to variable named $cores. Now I want to add this variable to .bashrc, so I ask user how much CPU cores he has and then ...
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1answer
350 views

Functions defined in .zshrc not found when running script

I have a function in .zshrc that mostly updates the PATH: my_function() { PATH=... } and some scripts that depend on it, e.g. my_script.sh starts with the following lines: my_function # do ...
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1answer
397 views

Capture Error of LS to file [duplicate]

#!/bin/sh if [ $(ls sample01.log | wc -l) = 1 ] then echo "File Found" > lsOutput.log else echo "File Not Found" > lsOutput.log fi But if sample01.log is not already existing my code already ...
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1answer
344 views

need to display hard error , transport error & soft errors above 2

iostat -En | nawk '/Hard Errors/ {line=$0;gsub(/.*Hard Errors:/,""); \ if($1>2) printf("%s\n",line); }' The output of this is c0t1d0 Soft Errors: 0 ...
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2answers
358 views

read file record by record and do transformation to the subsequent record based on above record and write into another file

Data file is fixed length file, and I want to read the file record by record and do transformations to the subsequent records based on the prior records (and write the results into another file). ...
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2answers
215 views

file command + how to view all results from file command

I use the file command in order to verify if file (PATH) is text/ascii file or encrypted file Because file command have allot of results ( small example in example 1 ) I want to get the all ...
0
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2answers
827 views

Bash script error trying to find directory of script itself: unexpected end of file

Borrowing graciously from this StackOverflow answer, I want to find the directory a script is running in so I can load relative paths for it on login: The script is pretty small right now: ...
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2answers
78 views

check if string represents valid path in BASH [duplicate]

I currently have a directory in a string, as such: DESTDIR="/var/files/mydir/filedir/" Note that this directory does exist. I made sure of that. I need to check if this directory already exists, ...
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1answer
1k views

Commands not found in shell script

I need to execute scp command without using expect command in script. How to use scp with password? I have tried with following code. HOST=lnx1 USERNAME=user PASSWORD=pwd PATH=/sample/data/ FILE=$1 ...
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3answers
451 views

How can I select columns based on a control file with invalid column numbers?

I have to generate the file dynamically from the source file based on the below control file. control_file.txt 1,3,5,-1,8,-1,4 The control file contains the position of columns which I require ...
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1answer
133 views

How to find files with the smallest size in a directory

I need to find all files of the smallest size in a directory. My code so far: #!/bin/bash dir="$1" printf "minimum file size: %s\n" du $dir -hab | sort -n -r |tail This code ...
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2answers
986 views

“bash: [: : integer expression expected” [closed]

I want this function to return one random word if there aren't any command-line arguments. I am modifying linuxconfig.org's random-word generator to run even when #$ -ne 1. function random-word { ...