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
39 views

Bash if statement not working properly [closed]

I have a bash statement to test a command line argument. If the argument passed to the script is "clean", then the script removes all .o files. Otherwise, it builds a program. However, not matter what ...
0
votes
0answers
5 views

Fine tuning of an informative replacement for rm [migrated]

I want to replace rm by a more informative variant: I would like to see which files will be deleted, along with their size, and I would like this information to use the same coloring as ls. I built ...
0
votes
1answer
36 views

How do I exec more than one command?

My login script ~/.profile ends with the command exec startx > ~/.xsession-errors 2>&1 I would like to run a second command foo when startx is done so I tried exec { startx > ...
0
votes
1answer
19 views

Redirect all GnuPG output to /dev/null

I'm doing key generation in a sort of batch mode with GnuPG (don't ask why): echo -e 'addkey\n4\n2048\n120d\nsave' | gpg --command-fd 0 \ --edit-key $master_key_id >/dev/null 2>&1 I ...
4
votes
3answers
56 views

Go from a String to an Array of “words” in Bash

I need to go from a string to an array where each entry is each word on that string. For example, starting with: VotePedro="Vote for Pedro" I need the array: Vote For Pedro Which I should then ...
3
votes
3answers
50 views

Wait for key in shell script that may get piped to /bin/bash

Consider the following shell script echo foo; read; echo bar Running bash my_script outputs 'foo', waits for the return key and outputs 'bar'. While this works fine running it that way, it doesn't ...
1
vote
1answer
49 views

Exiting a script called from another script via SSH

Suppose that bash script X is being called within another bash script Y. If I directly execute script X on a local machine, after X's completion, the program exits to the terminal. However, when I ...
0
votes
1answer
26 views

Running a command on different shell

While reading the answers of question Can bash write to its own input stream?, I found following command runs on zsh but not on bash : print -z echo mnciitbhu 1 . Is -z is an extension to print ...
2
votes
4answers
111 views

How to influence a bash while loop with a timed global variable?

I have a while loop in a bash script which should do something different at the beginning and at every 5 second interval. Any previous loop is allowed to complete. The 5s interval is indicated by the ...
0
votes
1answer
72 views

How to run multiple sudo commands over already opened ssh connection

I am trying to navigate from one server"USER1" to another using ssh as a user "USER2". ssh -t $hostname "sudo su - USER2; whoami; pwd" Post executing the above, I am able to successfully navigate ...
0
votes
1answer
32 views

Need to parse nginx access.log by minute, chunks for statistics - is there better way?

I need collect current data from it every minute to monitore amount of requests and errors. It's nginx's frontend log - with a lot of requests. It's formatted, rotated than archived every hour. So - ...
1
vote
1answer
56 views

What does colon (':') in bash variable resolution syntax mean? [duplicate]

Could you help me decode this assignment: jvm_xmx=${jvm_xmx:-1024} Can't understand, what it does.
2
votes
2answers
82 views

What is the shortest way to select the first available port in a certain range using Bash?

Aim: Select the first available port in a certain range. E.g., if port 600 is unavailable then the availability of port 601 will be checked. Attempt: The following script works as expected but is too ...
0
votes
1answer
32 views

PS1 variable inheritance between scripts and programs using bash in AIX

How to ensure that PS1 variable in AIX bash is inherited between cross calling of scripts and programs ? Suppose a program that give to the user a shell instance like the shell command of vi. This is ...
0
votes
1answer
51 views

What does PROG=${0##*/} mean in a bash script? [duplicate]

PROG=${0##*/} seems to parse out the shell script name, but it's unclear how that works. ${0} I understand is the first or 0th variable.
2
votes
2answers
45 views

How do I kill a process after detaching it from bash?

I have multiple scripts that detach a process from bash using nohup and &>/dev/null &. My question is, how do I kill the process after completely detaching it from bash. using killall or ...
1
vote
0answers
19 views

Build Script Help, Not Loading Modules

So I am writing a script to build and install Netcdf, but when I source it, it seems like some of the lines just are not running or are being skipped and I am unsure why. When I run the code line by ...
1
vote
5answers
114 views

list all files with extension .log except one

I would like to list all files with extension .log except the file backup.log. I have tried using this command: ls *.log -I "backup.log" But all the log files are listed, even backup.log! How ...
1
vote
3answers
71 views

Using a function defined in a parent script

I wrote the following script in the test.sh: #!/bin/sh compare() { if [ $1 != root ]; then echo "Fail" >> CAT1.txt fi } awk -F: '$4 == 0' /etc/passwd | cut -d: f1 | xargs -n1 -i bash -c ...
1
vote
1answer
68 views

Using only in-memory command history

How can I prevent Bash from writing history entries to disk? My ~/.bashrccontains the line trap 'unset HISTFILE; exit' SIGHUP but it doesn't have the desired effect. If I run history -c && ...
1
vote
2answers
125 views

Write bash_history to a file with a timestamp

I need help with the script below. The requirement is to capture command line history in a file with specific date and time of commands, when they were executed. The below script captures history ...
1
vote
2answers
208 views

Bash script to read file and echo different lines to output files [duplicate]

I have a log.txt file with various lines of strings and information. I want to write a script to read the log.txt file line by line and any line that contains the word debug I want to put that line ...
0
votes
1answer
16 views

format of a script which installs programs as root, but configures for a regular user?

I am writing some bash scripts to install and configure some programs. Because the script needs to install packages - I run the scripts as root - which itself is no problem (i.e. I have root ...
-1
votes
1answer
74 views

how to extract lines between 2 patterns, and save them to different files

hej all, Let' say that we have this file: rrows 35 cols 51 spin 2 %band5 efermi=0.012538 0.004352 0.004317 0.004213 0.004047 0.003828 0.003570 0.003291 0.003011 0.002754 0.002544 0.002408 ...
2
votes
2answers
77 views

Sort files with a specific extension by modified time and store them into an array

I have found many answers to sort the files of directory and even to save them in an array. Sorting Example ls -t Directory listing in array array=(*) My particular problem needs to sort files ...
0
votes
2answers
92 views

Explain the shell command: shift $(($optind - 1))

I am not a Linux guy but stuck in some Script which I have to read for my Project. So can anyone can help me what this command is doing? shift $(($optind - 1))
13
votes
3answers
573 views

Differentiating between running and being sourced in a bash shell script?

Either what I'm asking here is extremely unorthodox/unconventional/risky, or my Google-fu skills just aren't up to snuff... In a bash shell script, is there any easy of way of telling if it is ...
2
votes
5answers
131 views

Can't login to server with SSH because of a script in /etc/profile.d exiting with exit status 1

so I have this problem, I can't login to my server with SSH. See: ssh -v myuser@myserver debug1: Authentication succeeded (password). debug1: channel 0: new [client-session] debug1: Requesting ...
5
votes
3answers
158 views

Output Output of command to command line directly, NOT variable [duplicate]

I am on the bash shell and I want the output of a command to appear directly in the command prompt that appears after the command has executed ! Example of what I envision it, to illustrate my idea: ...
-2
votes
1answer
44 views

ls: No such file or directory [closed]

I have been messing around trying to install macvim to a higher version of 7.4. I finally got it working but now I get the error ls: No such file or directory when looking for a directory. I can ...
1
vote
2answers
54 views

Exporting a function from .profile/.bashrc

What am I doing wrong...? It's fine if I do this on the command line and then call it but not when I load it from .profile. Linux Mint Qiana, Bash 4.*, if it matters. function android() { command ...
5
votes
1answer
144 views

Logging bash output to a file

I'm trying to build vlc which is rather complicated and dependent on having the right packages installed, and keeps choking on errors. To trace all my steps I wish to output what I'm doing to a ...
11
votes
1answer
308 views

Why Ctrl+m and Ctrl+q wasn't used in bash shortcuts?

Recently I've been viewed through bash shortcuts key, and trying to find an appropriate one for my tmux activate key. And I find an interesting fact that ctrl + m and ctrl + q are not used in bash ...
3
votes
1answer
52 views

Parameter expansion in variable assigned with a wildcard

I have two files in my current folder (MA502) whose names are - MA502_TAAGGCGA-TCGCAGG_L001_R1_001.at.fastq MA502_TAAGGCGA-TCGCAGG_L001_R2_001.at.fastq I have many such folders - ex MA503, MA504 ...
21
votes
5answers
1k views

Can bash write to its own input stream?

Is it possible in an interactive bash shell to enter a command that outputs some text so that it appears at the next command prompt, as if the user had typed in that text at that prompt ? I want to ...
1
vote
0answers
23 views

-devilspie doesn't play nice with spawning new terminals

I'm trying to configure devilspie so that on detection of opening a certain directory it runs a script to mount that directory over a network. I don't think the script itself is too important but ...
2
votes
3answers
54 views

Split command and arguments, and put into variable in a bash script

I have a script that repeats the same (very long) grep command many times. I want to make the script more readable by cutting the line length, so I tried to put parts of the command into variables. ...
0
votes
2answers
64 views

breaking out of command loop but exit code not the reason?

I run the following: echo "while emacs;do echo $?;done;echo Exit code: $?;" | bash If I exit emacs through the menu or the close button, it prints exit code 0 and restarts. If I exit emacs through ...
-1
votes
1answer
41 views

Matching regular expression with delimited string in unix

Can someone help me in matching the below delimited regular expression in bash script: number|my_name|number I have tried the below but could not get it through end: sed -e 's/[^[[digit]]*//g
0
votes
1answer
21 views

Import list of IPs into DEVICE=eth0:X

I have a list of IPs I would like to import into my Linux VPS. They are not an IP range. How would I create a bash script that does this for me? 1.1.1.1 2.2.2.2 If they where my IP lists then it ...
1
vote
1answer
50 views

Display a line in a text file if variable matches a part in the line?

I'm making a stock checker. I have a file with all of the NYSE exchanges and their descriptions. The descriptions start on the first tab enter of the file. The file formatting looks like this: A ...
2
votes
1answer
41 views

View remote value of $PATH inside shell script

When executing this bash script, it only shows my local path. ssh ${REMOTE_HOST} 'bash -s' <<EOL set -e source ~/.profile echo $PATH # Commands here don't work because $PATH is ...
1
vote
2answers
69 views

Bash script with data from another file

I have worked on the following script which I want to use to easily add multiple Postfix as well as a few other things. Below is a small sample postmulti -e init postmulti -I postfix-$new -e create ...
0
votes
1answer
44 views

How to escape an input string in Bash [closed]

I'm using the jq tool to handle some JSON in bash. Just one problem, while using this line: PB_ACL="acl="`echo $IMGREQ | jq -r'.data.acl'` Result: echo $PB_ACL // acl= The expected value jq ...
1
vote
1answer
48 views

Find last line of a file for matching string?

I want a loop that runs infinitely over a file but always checks the last line to see if it contains the matching string if it does then echo that line and keep the loop running. What I have right now ...
4
votes
1answer
87 views

Is there a command line tool to manage unix signals?

Is there a command runner like env, nice, nohup, etc., that can run a program with modified signals? In my case, I need something to reset SIGINT to SIG_DFL. Why do I need this? Because ...
0
votes
2answers
22 views

Saving a piped value went wrong

I installed jq to handle some JSON with bash. But somehow piping the JSON string to jq in combination with saving it's output to another variable went wrong. TEST='{"foo": "bar"}' PB_SIG=$TEST | jq ...
0
votes
0answers
18 views

How to get back my splitted screen after I lost connection

I was executing the screen command with a splitted window in my CentOS server then I lost connection to it. I reconnected to my server and I did screen -r to get my screen back but now I don't see ...
5
votes
2answers
298 views

Why does `cat` seem to iterate over JSON arrays?

I'm puzzled by this behaviour of cat when trying to output a heredoc containing JSON in bash 3.2: input: $ cat <(cat <<EOF > {"x":[{"a":1,"b":2}]} > EOF) output: {"x":["a":1]} ...
11
votes
3answers
833 views

How to understand “cat > file_name << blah” command?

In following command cat takes the content of here-doc and redirects it to file named conf: cat > conf << EOF var1="cat" var2="dog" var3="hamster" EOF How to understand the order of ...