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

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2answers
399 views

Getting Group Names for List of Users

I have a text files with a list of users formatted like: name1 name2 name3 ... Calling the command groups gives the primary group name for that user. ex: bash$ groups name1 name1: ...
2
votes
2answers
803 views

add filename as text in the corner of an image file

I have a bunch of jpeg images. Say 001abcd.jpg, 002abcd.jpg, and so on. I want to capture the filename and add it as a text in the image itself in one corner. So the result would be, for example, the ...
2
votes
2answers
139 views

Copying new file and sending an email

I want to copy all files with the extension .beta from one directory to another and then send an email with following format. The following files have been moved from directory A to Directory B: 1. ...
2
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2answers
802 views

Allow another user to run a specific script as my ID

I have a script somewhere in my home directory. I need to give another user or a group permissions such that when they execute that specific script, it executes as though I am logged in and has all ...
2
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2answers
322 views

CRON Job To Execute Command On Low Memory

I have a situation where I may need to execute an SAP command line tool hdbsql when memory gets too low (to help clean out the HANA table cache). I'm not well versed in Unix/Linux, and was wondering ...
2
votes
2answers
51 views

sed replace after matching character

I have to change a properties file containing the property: ro.product.firmware=0.0.1 with a new value that is coming from a function called in a different section of my bash script. I cannot get ...
2
votes
1answer
136 views

Force a job to come in foreground when asked for user input

I'm currently working on an audit-script for a huge platform. In the main-script we use traps and in one of the traps I ask the user for clean up the files. The script has no output in standard output,...
2
votes
1answer
94 views

Finding business date within range

Please assist in finding only the business date (Mon-Fri) from the below (in bash) #!/bin/bash startdate=20141030 enddate=20141120 dates=() for (( date="$startdate"; date != enddate; )); do ...
2
votes
1answer
2k views

How can I check if rsync made any changes in bash?

I have a script which uses rsync to sync data in a remote -> local scenario. Immediately after the rsync command is run, a check to see if the error code equals zero or not. If its zero, further ...
2
votes
3answers
163 views

Extract a part of a string in a bash script

I have a variable with some text in it. I need to get a specific bit of information out of it. For example I have export OUTPUT="Running \"protractor:admin\" (protractor) task Using ChromeDriver ...
2
votes
1answer
215 views

I have a multi-line string that I need to iterate over, but I'm not using bash. Advice?

I'm using Dash because this is to run on my rPi. Bash is not an option. I'm rewriting a Bash script to work with Dash. I'm hoping to make it as POSIX-compliant (portable) as possible. The thing is it'...
2
votes
1answer
228 views

Using find and sed to copy 20th line of many files into one file

I have a folder called PKA1 Within this folder I have several folders named as: 1eV, 2eV .... 30eV Within each of these subfolders I have a file called PKA.dump I want to copy the 20th line of PKA....
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votes
4answers
228 views

How can I find the program I'm hiding in bash

Say I have PATH="home/bob/bin:/usr/bin". I am writing a bash script /home/bob/bin/foo that will do some munging and then call /usr/bin/foo. Of course I want to be able to use this script on ...
2
votes
1answer
760 views

cat to stderr while reading to end of file marker

Leaving aside the question of whether usage output should go to stderr or not, if you had to redirect the output of the cat command below to stderr, how would you do it? function usage { cat <&...
2
votes
2answers
135 views

grep with count of individual patterns

I have a file with MAC addresses (1/line with : as separator, sorted) and I need to find out how many times each of these MAC addresses appears in the file. I modified this: How to count occurrences ...
2
votes
4answers
76 views

Does it make a difference (e.g. performance-wise) if I execute a command from a bash script (vs the command line)?

Is there any difference between the following (e.g. performance-wise): $ make && cp bin/myexecutable inputfile.txt $workdir && cd $workdir $ <series of sed commands to modify ...
2
votes
2answers
4k views

How to delete old backups based on a date in file name?

I have a daily backups named like this: yyyymmddhhmm.zip // pattern 201503200100.zip // backup from 20. 3. 2015 1:00 I'm trying to create a script that deletes all backups older than 3 days. The ...
2
votes
1answer
231 views

attempting to put dynamic input data in a variable via cat method

I'm attempting to write a bash script that should be able to collect data from ttyS0 and put in a variable. I need to talk with a device on the serial line, that is a module able to receive AT ...
2
votes
1answer
1k views

Shell script to change directory of terminal and open a second terminal

I am new to writing shell scripts and I am trying to write a script to CD to a folder where my programs are saved for one of my classes, then have a second terminal open that ssh's to a server used ...
2
votes
3answers
12k views

How to include python script inside a bash script

I need to include below python script inside a bash script. If the bash script end success, I need to execute the below script. #!/usr/bin/python from smtplib import SMTP import datetime ...
2
votes
1answer
220 views

Intercept and modify commands in bash scripts

I have some scripts and some commands in the scripts are like this ./executable arg1 arg2 .. argn I want to change the above command to LD_PRELOAD=/some/lib ./executable my_arg1 my_argn arg1 arg2 ...
2
votes
2answers
183 views

How to return 0 if a pattern is matched from a file? [duplicate]

I have a binary that repacks android kernel (not mkbootimg). I'm making a script to automate the process. I don't want any output on the screen. So I have redirected the output to a file named foo....
2
votes
2answers
202 views

How to append word count of file to file without adding the total

I am running a bash script where I am appending the line count of the arguments, which are files, to another file. It does it correctly, but I keep getting a line that says "total X", X being the sum ...
2
votes
3answers
168 views

Is there a simple way to find out the last line executed in a bash script?

In answering this question please bear in mind that I am a beginner and a bit out of my depth. I'm running a bash script which contains a for loop which will run thousands of times. Somewhere in this ...
2
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2answers
62 views

Command to work on all files in a folder and output result to single file

I have a list of files, 10 to be exact, in a recipe folder. I must determine the number of occurences of each word in all the files and then order them according to these frequencies. I can get my ...
2
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2answers
2k views

Why double ampersand chained conditions runs in background together the last one?

I have some conditions for some background job to run: condition-command && condition-command && background-job & The problem is: I want the conditions to block until the job ...
2
votes
1answer
708 views

How do I wait for all child processes but one to finish executing

I am starting a number of processes in the background of the scrip that I'm writing. I want to wait for some of them to finish before the end of each iteration of a for loop, but there is one process ...
2
votes
1answer
5k views

Why am I getting “too many arguments”

Here's a part of my script that is telling me that I have too many arguments on line 3: #!/bin/bash export LC_ALL='C' if [ `echo "*file 2" | grep -o ^.` = '.' ] then echo success fi Anybody ...
2
votes
2answers
864 views

Shell script to merge files with same names

I have a directory of files such as: file.1111111_1.pdf file.1111111_2.pdf file.2222222_1.pdf file.2222222_2.pdf … file.1234567_1.pdf file.1234567_2.pdf … file.aaaaaaa_1.pdf file.aaaaaaa_2.pdf … file....
2
votes
2answers
90 views

Output piped content to file and show number of lines in the file on stdout

I would like to use tee to pipe content from stdout and stderr respectively into files (in fact append it with > >(tee -a $filename)). However, instead of seeing the contents appended to the ...
2
votes
1answer
494 views

How to print a bash variable that has an array as value

I wrote a script for my dwm statusbar. One part of it is finding the current cpu usage for every single core on my system. I figured out a way myself but I would need some help fixing a bug in this. ...
2
votes
2answers
141 views

Livesearch with first 10 matches as preview for zsh-history?

I have seen a history-livesearch with a preview, that shows the 10 first matches in the history in a list below the BUFFER-line, which is updated on every keystroke, and acts like the standard ctrl+r ...
2
votes
1answer
52 views

Comparison of columns in two files and appending the first file

I need a help on this :- I have a file : emp.txt 21356 suresh 12/12/2012 23511 ramesh 11/06/2011 31456 biswajit 09/08/2013 53134 archan 06/02/2009 first field:- employee id, 2nd field is name and ...
2
votes
2answers
1k views

Replace value within single quotes in a line that contains certain word using sed command

I have a line as below in a html file, shahar.push(['remoteUrl', 'staging.zazzercode.com']); Depending upon environment, I want to replace the remoteUrl value with sed command. eg, shahar.push([...
2
votes
3answers
6k views

Script for testing SFTP login status?

I need to perform an automated backup task that connects to an SFTP server. The first stage involves testing the server connection by connecting to it. To be absolutely sure that it is connecting to ...
2
votes
2answers
1k views

Pass a command to ROOT from a shell script and having it stay open

I am writing a bash script to perform some analysis using the program ROOT. I want to run some initial command to load the result of the analysis, then continue using ROOT interactively. The analysis ...
2
votes
2answers
810 views

How to clear the input in Bash

I have a bash script that is reading quite a bit of data /dev/random. I need the user to type randomly to seed the random daemon. However once the script completes everything typed will get dumped to ...
2
votes
2answers
82 views

Call the script after disconnecting from server

I have a script I made for work that will call a function that takes an argument. I use the arguments to ssh into our servers. My question is: Is there a way to call the method so that if/when I get ...
2
votes
1answer
689 views

Using xargs with git

I am trying to practice using xargs. I tried the following, passing the SHA1 via xargs: $ git show SHA1 --name-only I also tried: $ git log --author=jim --grep="patch" |head -n 1|cut -d ' ' -f2|...
2
votes
2answers
11k views

Email using shell script

Is there a possibility to add multiple e-mails to a single variable so that when the shell script is run, it sends a mail to all the specified emails?
2
votes
1answer
61 views

Why does sed not remove my empty lines?

Why does not this sed command remove empty lines? sed -e 's/\r//g' -e '/^{$/d' -e '/^}$/d' -e ':begin;$!N;/^state-text: {[[:space:]]\n/s/\n//;tbegin;P;D' -e "s/'/''/g" -e '/^$/d' <<< $myvar ...
2
votes
1answer
1k views

Why is my tar in a script behaving different than using tar manually

I'm writing a backup script for my email and cloud service. For simplicity, I only posted the mail-backup part here. Basically, I have a Host-Machine with some Virtual Boxes running in it. These ...
2
votes
2answers
490 views

What is the best tool for automating the building 32-64bit libraries for Unix & Windows building C++ software, replicable by users and machines?

Is there a system or product that can be used in automating the process of building 32bit and 64bit libraries for multiple platforms (Solaris (Sparc & x86), and windows) used in building C++ based ...
2
votes
1answer
470 views

grep and command-line variable substitution

In the following command sequence, $ grep -E '^.{11,22}John' emplist Operations John Thompson PARTHawks Cher Sales John Jacobs FULLHawks Davinder Singh Finance ...
2
votes
2answers
604 views

Find and rename files adding part of the path to filename

I have a folder with two level of subfolders inside it. Inside the second subfolder, there is a jpg file. All the jpg have the same name: cover.jpg Example: /home/user/folder001/folderAAA/cover.jpg /...
2
votes
1answer
409 views

How to create an executable bash script for these commands?

I wish to create an executable bash script that will run the following commands as root, that is, using sudo su iptables-save | awk '/^[*]/ { print $1 } /^:[A-Z]+ [^-]/ { print $...
2
votes
3answers
3k views

Redirect output of a command to two different files [duplicate]

Redirect output of a command to two different files I know I can use tee, but I dont want the output to be printed on the screen I want them to be printed only on the file example : ls > pk.txt ...
2
votes
1answer
799 views

Using Fifo hang script

out="$katalog/out" # wyjscie fifo="$katalog/fifo" # wejscie mkfifo $fifo touch $out [...] #k ./a.out <$fifo >$out & pid=$! [...] # get input line by line loop start echo "$liniain" >> ...
2
votes
2answers
438 views

Sed? Stripping all formatting, i.e line breaks and whitespaces, from a report text file, while masking out certain pieces

I am working on a project in which I need to remove all formatting from a text file including whitespaces and line breaks, then replace any colons with pipes. I've made some headway but I cannot find ...
2
votes
3answers
5k views

XOR of a shell variable and a binary file

I have a password stored in a shell variable (which was read from command line input). I also have a keyfile stored in a file (which was created using dd and /dev/urandom). Since I want to require ...