Questions tagged [bash]
Questions specific to GNU’s Bourne Again SHell, as opposed to other Bourne/POSIX shells. For questions about Unix shells in general, use the /shell tag instead. For shell scripts with errors/syntax errors, please check them with the shellcheck program (or in the web shellcheck server at https://shellcheck.net) before posting here.
25,533
questions
0
votes
3
answers
75
views
Bash expansion repeat a string n to n times
I'm trying to find combinations of characters that fit a (c)v pattern for up to n syllables, and so started by using expansion like echo {,p,t}{a,i} for all the possibilities for one syllable (using ...
- 11
0
votes
0
answers
30
views
ipsweep bash script not working (name or service not known)
I coded a bash script for an ip sweeper however it keeps giving me ths "name or service not known" output. Here is the code :
And here is the output when I run the script :
Can you please ...
0
votes
0
answers
38
views
version-check.sh: line 1: !/bin/bash: No such file or directory [closed]
I am trying to build an LFS system. When I run the script it tells me version-check.sh: line 1: !/bin/bash: No such file or directory I have looked inside my files and the bin/bash file is present. I ...
0
votes
0
answers
14
views
How to use entr to duplicate a folder every time a contained file changes
I've never used entr before, but I intend to write a command in /etc/rc.local to copy the contents of a folder into another folder, every time a change is made inside the original folder.
For this ...
- 103
1
vote
1
answer
26
views
Access values of associative array whose name is passed as argument inside bash function
I've some associative arrays in a bash script which I need to pass to a function in which I need to access the keys and values as well.
declare -A gkp=( \
["arm64"]="ARM-64-bit" ...
- 13
0
votes
1
answer
41
views
Is there a tool for collapsing output of a command base on regex?
Let’s say I have a command that outputs the state of some application. This command runs forver (or until C-c) and outputs a single line when something happens inside the application. It outputs the ...
- 101
0
votes
2
answers
57
views
What is the hot key to show the next command of the previous command in history in Linux/bash?
In Windows cmd window, let's say I type and execute 40 commands like this:
echo 1[Enter]
echo 2[Enter]
echo 3[Enter]
...
echo 40[Enter]
If I decide to repeat the 40 commands again, in the same order, ...
- 113
1
vote
4
answers
360
views
How to get the current value of LC_CTYPE etc. in Bash?
Basically, how to achieve this in Bash? Parsing the output of locale - declare "$(locale | grep ^LC_CTYPE | tr --delete '"')" - seems yucky, as it involves four separate commands. ...
- 50.9k
0
votes
4
answers
72
views
Loop through array in specific order
I have an array that may or may not contain BMC, and I'm looping through each element of the array. If it does contain BMC I want BMC to be the last iteration of the loop.
The array is created with ...
- 36k
0
votes
1
answer
49
views
Can't interact with a file with an apostraphe directly in bash
I have a file titled "I'm Here.mp3" when I try to interact with it with ls, cp, mv, anything, it returns cannot stat "./I'm Here.mp3": No such file or directory.
I tried double ...
- 3
0
votes
2
answers
62
views
Fitering rows of one CSV file based on two values from another file in Bash
I have two CSV files.
One is long with columns: Chr_Name, h, j, start_pos, end_pos.
Another is short file including columns Chr_Name and position.
I need to filter the rows from the first file based ...
- 1
0
votes
1
answer
69
views
How to compress multiple files quickly using tar
I need to transfer multiple files to a HPC cluster. Currently, I've been using the scp command but it takes about 10 minutes or more to transfer one file (about 1.4GB each). I've seen that using tar ...
- 1
7
votes
2
answers
976
views
LD_PRELOAD does not work and LD_DEBUG shows nothing
I use LD_PRELOAD to overwrite the read function. For a minimal test application it works fine, but if I test it with a larger application it does not work anymore. Also LD_DEBUG=all does not show ...
- 203
1
vote
3
answers
62
views
Run nested local bash functions via ssh
I have a script like this that declares many functions which use another functions, etc.:
#!/bin/bash
function a {
...
}
function b {
...
a
...
}
...
And another script that uses ...
- 133
1
vote
1
answer
47
views
Is there a way to make a comment after a "\" has been used to split a shell command onto differemt lines? [duplicate]
I am using arch and bash. Everything is up to date.
I have this command which works just fine
yad \
--timeout=2 \
--undecorated \
--posx=1200 --posy=633 \
--title=" " \
--window-icon='/home/$...
- 799
1
vote
2
answers
42
views
How do I make sed delete a block of indented text below a non-indented line that also contains particular regexp, but not beyond?
I've been fighting with GPT, the sed documentation, and regex for almost my entire day. I'm trying to parse through files that contain cisco prefix-list configurations and print out the lists that ...
- 13
0
votes
0
answers
41
views
glob expansion not working even with shopt -s extglob set
I am trying to chmod -R 644 /tmp/work/* in bash script, however I get following error:
#!/usr/bin/env bash
shopt -s extglob
set -eu
mkdir -p /tmp/work/
chmod -R 777 /tmp/work/
sftp -o ...
- 141
0
votes
1
answer
36
views
how to execute command and log only the command to a file
I'm trying to run a command and log only the command to a file. I've tried using exec 4>test|command >&4|exec 4>&- but doesnt' work. If I run the commands separately it works but ...
- 11
0
votes
1
answer
189
views
what does this bash snippet do?
I am not very bash-fluent, but I really need to comprehend what does the following mean and what is the explanation?
The code is not mine, but I trust the source
I am especially bothered by the ...
- 135
1
vote
1
answer
229
views
Is there a way to alias "redirect stdout and stderr to a file"?
Relevant Context:
Redirect standard out
command > file
command 1> file
Redirect standard error
command 2> file
Redirect standard out and standard error to separate files
command 2> ...
- 783
0
votes
1
answer
48
views
how to write function with nested commands [duplicate]
I'm trying to write a find and cd function like so:
findcd () {
cd "$(dirname "$(find '$1' -type '$2' -name '$3')")"
}
to be called like so:
find . f [FILE_NAME]
But it's ...
- 127
-5
votes
0
answers
60
views
I need to sort files in recursive list, but there are some difficulties [closed]
I got some problems when I was doing the task:
Output the first four elements of a recursive list of file names and attributes in the lib0 directory containing the string "ra", sort the ...
-1
votes
0
answers
58
views
How do I make a .bashrc shell function interactive?
eshark() {
ssh root@$1 'tcpdump -i $2 port 5060 -vv -s0 -Uw - ' | sudo tshark --interface - --print -w $3.pcapng
}
When I run this, on a Linux machine, it says capturing on stdin whereas when I run ...
-4
votes
2
answers
159
views
Append not working well in bash [closed]
I noticed that the operator ">>" doesn't work well in my script and I don't know why. I have a script like this:
for file in $(ls folder)`
do
echo $file >> text.txt
done
Into ...
3
votes
2
answers
322
views
Piping and input stream redirection to same command, which input does command take?
I was trying to run the command given below
cat numbers.txt | sort < words.txt
The above command has a pipe from cat command feeding to input stream of sort command. But at the same time, input ...
- 133
0
votes
2
answers
40
views
Unable to pass AWS CLI commands in double quotes in json syntax
I'm working with the below script,getting syntax error as unable to fetch credentials from secrets manager. "username":"AWS CLI command of access Key i have entered", "...
- 17
0
votes
0
answers
18
views
Why does the output in following command get written to second file rather than first file [duplicate]
I was learning about I/O redirection and tried out the following command.
ls -l /bin/ > bin_contents.txt > bin_contents_copy.txt
I do understand that redirection doesn't work between files. But,...
- 133
0
votes
0
answers
11
views
mixup TCP sessions in pcap file to new pcap file
I need to shuffle TCP sessions from pcap file to new file. How can I do it? The following scripts don't work for me.
To mix up sessions in a pcap file using Tshark or Wireshark, you can use the ...
- 41
1
vote
1
answer
17
views
How to sync the commands I am typing with a document in Google docs?
I am working on installation of a software and making lot of changes in a linux box. Lot of times I am running 'history' to get list of commands and copy-paste into a Google Docs. Then I clean it for ...
- 11
0
votes
0
answers
19
views
Mailx call in shell script suddenly sending blank messages
Similar to what was reported in posting, MAILX sends an email but with a blank subject and body text, I have an Oracle EBS 12.2 server that's using a concurrent program (java) to invoke a shell script ...
- 1
0
votes
2
answers
36
views
renaming files based on matched pattern in another file
I have a list of files:
out_CCGCGGTT+CTAGCGCT_R1.fq.gz
out_TTATAACC+TCGATATC_R2.fq.gz
out_GGACTTGG+CGTCTGCG_R1.fq.gz
out_AAGTCCAA+TACTCATA_R2.fq.gz
...
the adaptor IDs (between the two underscores, ...
- 1,016
0
votes
1
answer
49
views
bash: string variable contains asterisk. how to use this variable for searching etc with grep, sed?
Have a nice day
I have got text file (zz.txt):
Chemical name
3-Aminopropane-1-sulphonic acid
Synonym(s)
--
Homotaurine * Tramiprosate
--
Chemical name
Common name and synonyms
...
I have variable
s=&...
- 3
0
votes
1
answer
33
views
How to reuse matched value in bash globbing? [duplicate]
I was wondering whether it is possible to reuse whatever was matched in a path with globbing? (Just as it can usually be done with regex substitutions?)
I'm aware that there are other solutions for ...
- 115
1
vote
1
answer
53
views
How to auto connect to wifi in coffee shop with bash script
I'm using Arch and bash and Openbox and everything is upto date.
Hopefully this will help a few people
I'm often in Starbucks.
The method to connect is to their free wifi in the Uk is to
Connect to ...
- 799
0
votes
1
answer
47
views
Bash script variable syntax: with some commands it works, with others it does not [duplicate]
I do not understand the behaviour of this variable:
SSH_CONFIG_FILE="~/.ssh/config"
echo $SSH_CONFIG_FILE
ls -l $SSH_CONFIG_FILE
ls -l ~/.ssh/config
This is the output:
~/.ssh/config
ls: ...
- 561
4
votes
4
answers
615
views
Can I extract complete dates from file with grep command?
I need help using grep to extract a zoned date time from a file on a Linux system.
Source file is a XML with the data below:
<item start="20231010073000 +0100" stop="20231010100000 +...
- 43
0
votes
0
answers
30
views
Open GUI linux terminal in non-interactive mode
It would be helpful if I can open a terminal and run commands exactly as if they would be run by a non-interactive bash script, to test whether certain commands work in non-interactive mode without ...
- 125
1
vote
2
answers
657
views
How to modify a gzipped file with sed and then zip again the file?
I have a .vcf.gz file, with the following aspect:
#CHROM POS ID REF ALT
chr1 10894 chr1:10894:G:A G A
chr1 10915 chr1:10915:G:A G A
...
- 21
0
votes
1
answer
52
views
bash get output from command
I try to make a script for macOS that informs me about available software updates:
result=$(softwareupdate -l)
if [[ $(echo $result) = *"No new software available."* ]]; then say yes;fi
But ...
1
vote
1
answer
47
views
nnn file manager not allowing me to press r key for batch rename
I am using Arch and bash.
All packages are current and up to date.
I am using the nnn file manager.
I go into nnn and make a selection of 3 files by pressing the space bar while over each of the three ...
- 799
0
votes
2
answers
83
views
Test if all three filetypes are present in a directory
I want to detect that there is one of each of the following filetypes in a directory .png , .txt, and .tar.gz.
The following works correctly when testing for two of them
shopt -s nullglob
MYDIR=/...
- 187
0
votes
3
answers
52
views
Use bash to overwrite old file with a new file named according to current date
I am a complete beginner with linux, and need help making a bash script to create a file with a specific date in the file name.
I have a directory called /backups/, in which I would like to create a ...
- 187
0
votes
0
answers
49
views
Bash AutoStart script does not copy files from shared folder
I have added a startup bash script to a device running Raspbian (Debian GNU/Linux 11 (bullseye)).
This is my script:
SysmacApp.sh
#!/bin/bash
mkdir -p /home/pi/App;
mkdir -p /home/pi/Shared/Service;
...
- 101
0
votes
1
answer
49
views
How to list process with their depth?
I have a slightly different process tree question. I need to list the process and their depth in scalar value. pstree gives the result in a "graphic" manner.
root 100930 0.0 0.3 ...
- 875
-1
votes
2
answers
77
views
Copy file from Server A to Server B
I have requirement to copy files from Server A to Server B
And then move the copied files Server A to Archive folder
I have written the script, but it takes the directory name differently.
Copying ...
0
votes
2
answers
45
views
sed: update 2 similar variables in a file but keep the upper and lowercase
I have 2 variables in a file like below that I need to assign a new value inserted by one user input: read -p "Enter CName Name : " CName
sid=C02SBX
SID=C02SBX
When I run the following ...
- 13
0
votes
2
answers
33
views
How to extend piped command by contents of variable?
I would like to extend this line that calls /usr/bin/mplayer for recording an audio stream.
The referring script record.sh could get called multiple times in parallel and I need to know in which ...
- 11
4
votes
5
answers
1k
views
How can I make this script run in the background?
#!/bin/bash
# Get the battery percentage for battery 0
battery0_percent=$(cat /sys/class/power_supply/BAT0/capacity)
# Get the battery percentage for battery 1
battery1_percent=$(cat /sys/class/...
- 55
0
votes
1
answer
82
views
Run `git commit -m` with single quotes in zsh
I sometimes use characters such as ! and $ in commit messages, they need to be manually escaped, but not if you use single quotes like this git commit -m 'My $message here!'. I tried to write a ...
0
votes
2
answers
51
views
How to define a multiple page ranges for pdftk with a bash variable
I'm using Arch linux, Openbox window manager, and bash.
Everything is up to date with the latest versions.
Can anyone tell me why I can't get the "$page_range" variable to show up within ...
- 799