Questions about bash only, as opposed to other Bourne/POSIX shells. For all Bourne/POSIX-style shells, use the /shell tag instead.

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0
votes
1answer
15 views

Copy files to a destination folder only if the files already exist. but the source files have a different file extension

Copy files to a destination folder only if the files already exist. but the source files have a different file extension. i.e I have a backup of some files with ".desktop.in" extension and I want to ...
0
votes
0answers
13 views

Running a script during booting/startup; initi.d vs @root

I am currently trying to understand the difference between init.d and @root for running a script at startup/booting of the system. The use of @root is some what simpler by simply going into crontab ...
0
votes
0answers
29 views

how to locate a name-not-specified file in bash?

I have a bash like this to easily upload a file to my server: FILE=../"$1"/1.txt scp 1.txt remoteserver #upload the file to a remote server. The $1 is for input directory and I have a lot of ...
0
votes
0answers
42 views

What's the most efficient way to find out what is consuming disk space?

I usually check disk space consumption by running du --max-depth=1 -h / but for some reason, it's taking a long time on one of my servers. What's a faster way of doing this?
-6
votes
0answers
27 views

Script for compare two file permissions

create dir, create two files with diff permission. Now write a script to test the permisiion of these two files. If its same then display the filename with its permission. if not display the ...
0
votes
1answer
19 views

Error with sed on MAC OS X invalid command u

Im french sorry in advance for my bad english... So i have an error on MAC OS X when im using sed sed -i '' '/user_pref("mail.identity.id1.reply_on_top", 1);/ a\ ...
1
vote
1answer
36 views

loop through multiple folders and perform commands then write to file

I have 10 folders that I want to loop through while executing the following command: awk 'FNR > 1' *.csv | sort -sk 1,2 | sort -sk 3,3 > ${f}_appended.dat With a for loop wrapper, like ...
1
vote
1answer
43 views

Shell script runs diffrently based on working directory.

I have a script which runs differently based on current working directory. Basically it processes an .ini file and takes parameters from it and runs mysql backup. Script is running as root user. ...
1
vote
1answer
38 views

cd to my folders shows me an error

I just logged out my system and logged on. And i tried to get into my folder cd /u/folder It says Too many levels of symbolic links. But it worked yesterday. What could be the reason? I found ...
2
votes
1answer
19 views

Running a constructed command from bash script

I constructed a command like this in a bash script a="my_cmd"; a="$a --verbose"; echo $a; $a; It works and executes my command correctly. But when I add an environment variable to the mix it ...
2
votes
2answers
35 views

Invoke subshell command with loaded rcfile

I have some Python code that does: (this is a simplified version) shell = os.environ['SHELL'] os.environ['PATH'] = ... # some new PATH value if call(shell, '-c', ...
1
vote
0answers
53 views

Source code of the patches for Shellshock

I have a project for my grad level OS class, and I have decided to choose the Shellshock vulnerability bugs as my topic. There is a lot of great information out there, but I was curious if it is ...
0
votes
3answers
29 views

Renaming multiple Files, Bash Script, preferably with an Addition

Hello you wonderful people, I have a little problem creating a Bash Script. I have 7000 image files (dicoms). These files belong together and should be in order in ONE directory. However, the program ...
0
votes
3answers
50 views

How to use password in shell scripting

I am writing a script which greps for for multiple files from 3 log files. One of the log file is created as superuser and every time it executes it prompts for password. How do I put it the same ...
0
votes
0answers
22 views

bash command to simply print new bash commandline like [tom@cerulean ~]$ [on hold]

My shell script used carriage return '\r' to erase my current [tom@cerulean ~]$ bash line to print an information (that is run asynchronously then returned when done). I want something that will to ...
0
votes
1answer
19 views

cron: output of a script?

I've got a cronjob that looks like this 0 0 * * 7 [ $(date +\%d) -le 07 ] && /home/archiver/archiver.sh &> /home/archiver/output And it works from the cron+bash perspective in that ...
1
vote
1answer
39 views

When did bash quit exporting SHELL?

I upgraded a Debian box from stable to Jessie and I noticed that SHELL is no longer exported, so screen and similar programs start dash for subshells instead of bash. When was this change made and ...
2
votes
2answers
50 views

How do I swap the two last command line arguments?

$ ln -s ./dir/target.txt /path/to/source.txt{cursor here} How do swap file typed filenames in command line? Alt+T swaps words, not filenames, resulting in ln -s ./dir/target.txt /path/to/txt.source. ...
8
votes
4answers
603 views

Spaces next to pipes

I've seen history | grep blah and history |grep blah; and history|grep blah also works, though no one ever seems to use it. Is there any significance in the spaces (e.g. piping to/from different ...
0
votes
2answers
25 views

use backquotes in a script [on hold]

Why this difference between echo $Date and echo "$(date +%s_%kh%M_le_%a_%d_%b_%Y)"? beginning=$(date +%s) diff="0" rest="$1" tmp="0" now="0" Date=`date +%s_%kh%M_le_%a_%d_%b_%Y` echo -n "$1" while [ ...
0
votes
2answers
39 views

Gzip file but excluding some directories|files and also append current date

I'm looking for a way to create a .tar.gz file from a directory but I have some doubts. I'm know that the command for create the file is: tar -zcvf /path/to/compressed/file.tar.gz /path/to/compress ...
3
votes
1answer
51 views

How to swap two commands in bash?

Say I have command A and command B but I want B to run when I type A and vice versa. I've tried alias A='B' alias B='A' But this doesn't seem to work for some reason. How do I do this? EDIT: ...
3
votes
1answer
25 views

How to sort an associative array and retain the keys?

I have an array with filenames as keys and a numerical value as values. MYARRAY[00001.jpg] = 31 MYARRAY[00002.jpg] = 200 MYARRAY[00003.jpg] = 98 I need to sort them so they are ordered by value. ...
1
vote
0answers
38 views

Bash cannot see PATH update

I am running Debian on a VM. I login to the GUI and go to Applications > Accessories > Terminal. # echo shell: /bin/bash I modified ENV_SUPATH, ENV_PATH inside of /etc/login.defs. I restarted ...
1
vote
2answers
25 views

Does X mangle prompt environment variables?

I'm starting it with startx. Before that I have PS1 in my environment: $ cat /proc/self/environ | tr '\0' '\n' | egrep '^PS' PS1=[\u@\H \w] PS3=> PS2=> PS4=+ From inside X I get: $ cat ...
1
vote
1answer
22 views

Why did a recent Ubuntu 14.04 update mess up my PS1 prompt?

I recently updated my Ubuntu 14.04 using the software update. This caused some problems. Initially I couldn't open up a new terminal window due to unknown errors with my .bashrc I had to use ...
0
votes
2answers
26 views

When is /etc/bash.bashrc invoked?

What is this file anyway? Documentation makes no mention of it. And it's not supposed to be run automatically (version 4.3, 2 February 2014): Invoked as an interactive login shell, or with --login ...
3
votes
1answer
39 views

How to append MD5 checksum of email content in bash?

I found some lines of output missing from an auto-generated email notification that was dispatched via cron. Having confirmed that there is no AVC error, I want to find out if the integrity of my ...
3
votes
3answers
86 views

spawn - command not found!

I am using Mac OS X 10.9.4, following is my script to copy files from local machine to different host #!/bin/bash #!/usr/bin/expect echo "I will fail if you give junk values!!" echo " " echo "Enter ...
2
votes
1answer
55 views

Test if postfix is running

I'm searching for a reliable way to test if postfix is running from inside a bash script. My first attempt was simply trying pidof postfix, which doesn't work. Then I tried to get the postfix ...
0
votes
0answers
5 views

Generating a .img from tarball: The /dev/loop devices [duplicate]

I'm trying to make a .img from a tarball using the following script: #!/bin/bash # Packages required # dosfstools parted # Can be run on any Linux system # loop.max_part=15 must be in kernel ...
1
vote
1answer
80 views

Swap two files in bash [duplicate]

How do I swap two files in Linux console with minimum typing? Boring approach: $ mv file1.dat fileX.dat $ mv file2.dat file1.dat $ mv fileX.dat file2.dat
4
votes
2answers
69 views

Use lines in a file to produce string and file name

I have a file, foo.txt, that has a folder name on each line: folder_1 folder_2 folder_3 And I'd like to do something like this: cat foo.txt | xargs -I {} echo 'function {}() { return stuff; }' ...
0
votes
1answer
32 views

How does `ls` know whether it's piped or printed [duplicate]

ls normally prints like this: 1 1249 1653 23 33 4581 6202 6447 789 836 903 config.gz kpageflags sysrq-trigger 10 1253 1658 24 34 4582 6206 648 79 837 ...
0
votes
1answer
37 views

Why does the input to xargs is 1 string but without is strings in separate line?

I am trying to pipe file to rm via xargs. I understand that what I am tryng to do could be done by git clean but I am practicing the cli. I tried this: for files in $(git status --porcelain| sed ...
0
votes
1answer
17 views

Values from two lists are not processing correctly within two nested loops

I am trying to pass some values contained in two lists to a simple echo within two nested for loops (the echo is used to look at what is generated inside the inner loop). But the results are not ...
2
votes
3answers
61 views

How do I use inserted values using getopts

I have this bash code combined with getopts and if I understood getopts correctly OPTIND contains the index of the next command line option and all the command line options provided to shell script ...
-1
votes
1answer
24 views

using the sed command in bash show output in a new text file? [on hold]

Hey everyone I am new to the world of UNIX/Linux.My professor wants my class to use sed command to display output in a new text file but did not give us the commands; any help would be useful thanks
0
votes
0answers
17 views

Using a custom script for cron jobs mail notification

After coming across Mailgun I would like to write my own script to use their API in order to send mail notifications from cron jobs — avoiding in this manner having to worry about installing a ...
1
vote
3answers
53 views

Traverse all subdirectories in and do something in Unix shell script

I am new to bash scripting. I am working on a shell script and got stuck from last 3 days. I want my shell script to visit all subdirectories in a main directory. Do something in directories, sent ...
0
votes
0answers
30 views

Unrecoginzed option: using 'getopt' cmd in shell script [on hold]

What is wrong in the command: if ! options=$(getopt -n myscript -l a:,b:,cc:,dd:,ee:,ff:,gg:,hh: -- "$@"); then exit 1; fi I get an error msg: mhagent: unrecognized option '--hh' options=' --aa ...
1
vote
1answer
28 views

if command in find -exec

I was just trying to list all directories and files under current directory and also write if they are file or directory with the following command: find -exec echo `echo {} : ;if [ -f {} ]; then ...
1
vote
2answers
43 views

Extracting numbers with a decimal point from ls output in Bash

I would like to extract the numeric part of the file names that begin with "hsli" and end with ".h5" in Bash on Ubuntu 14.04.1 64-bit LTS. My ls -l hsli* output is as follows: -rwxrwxrwx 1 ongun ...
0
votes
2answers
29 views

What I am doing wrong with this bash variable? [closed]

How can I insert a variable into a command? In the case below, I need to concatenate the command with the variable file name. #!/bin/bash # Define a timestamp function timestamp() { date +"%D-%T" ...
1
vote
1answer
37 views

How can I get $PATH to always include $(pwd)/sub_directory/.bin

If the path ~/dev/project1/node_modules/.bin/ionic exists, and my working directory is ~/dev/project1, I would like to be able to just type ionic and hit enter. I could include all those ...
-5
votes
1answer
25 views

Remove characters from string with sed [closed]

I have this header: >tr|G3Q381|G3Q381_GASAC Uncharacterized protein OS=Gasterosteus aculeatus PE=4 SV=1 and I was thankfully helped on here to get it to: >G3Q381_GASAC but now I need to ...
2
votes
1answer
21 views

Show shell greeter only on initial login

Is there any way to show a greeter (motd kind of thing) only on initial login, and not when you do sudo su? Here's my current .bashrc: #!/bin/bash # # ~/.bashrc # # If not running interactively, ...
0
votes
0answers
12 views

PHP execute find + cp from page

I would like to copy some files from one folder to another in a Linux system through the use of PHP's methods exec or shell_exec. Currently, the bash shell executes this line correctly and the files ...
0
votes
1answer
38 views

Detecting function circular references in bash

Why does the following idiom not work in bash 4.1.0? if [[ "${FUNCNAME[*]:1/$FUNCNAME/}" != "${FUNCNAME[*]:1}" ]] Here it is in context... function isCircularRef_test () { # ### Seems like ...
-1
votes
0answers
43 views

replace first string before first space [closed]

how to replace first string before first space? NC_009925.1_13653 [754389 - 754574] Acaryochloris marina ATTCCTGATTCTCTTGATGAAAGTAACATTATGGATCAT... TATGATCCATTCAGGCATGATGCAAGGCGCTACCCCCAA... 110311 ...