All Questions
Tagged with bash-script or shell-script
16,789 questions
0
votes
0
answers
14
views
how to convert hex memory dump to Docsis config file?
Hex memory dump is Docsis config file. Is it possible to convert this hex dump info valid Docsis config file? Preferably, using Perl and DOCSIS::ConfigFile module. (or Python scripts, python-docsis). ...
- 1,473
0
votes
0
answers
31
views
Arch Linux start script
Hi I was just wondering if this script looks ok I run it after I login thanks.
#!/bin/bash
echo "hi, starting wifi, nft and desktop"
sudo ls
sudo systemctl start wpaStart.service
sudo nft -...
- 119
2
votes
1
answer
196
views
Replacing the domain string in the compiled binary file with an IP address
Just in theory: is it possible to replace the domain string in the compiled binary file with an IP address by editing a binary file in place with sed? (IP address belongs to a different domain, but ...
- 143
0
votes
1
answer
35
views
Sorting output from find like tree's output
Here is a sample directory tree as it would appear if it were sorted in character code order (i.e., directories are not listed first):
${PREFIX}/
.bashrc
.include.sh.d/
common.sh
...
- 4,458
11
votes
1
answer
1k
views
Is there any difference between [[ -n $1 ]] and [[ $1 ]] in bash?
The test [[ -n $1 ]] yields True if the length of string is non-zero.
But I've seen elsewhere and have tried using just [[ $1 ]] without the primary -n and it seems to have the same effect.
Is there ...
- 436
1
vote
1
answer
66
views
Bash: only the first long option is being processed
Suppose we have the file ./testing with contents
#!/bin/bash
# Flags
# Source: https://stackoverflow.com/a/7948533/31298396
TEMP=$(getopt -o ''\
--long first,second \
-...
- 145
2
votes
1
answer
93
views
Bash: function in a script with flags
Using https://stackoverflow.com/a/7948533/31298396, we can implement flags for a script testing as follows:
#!/bin/bash
# Flags
# Source: https://stackoverflow.com/a/7948533/31298396
TEMP=$(getopt ...
- 145
0
votes
4
answers
63
views
Mount a partition from a script unless it is already mounted
I would like to mount a partition of an external hard drive from a script using
udisksctl mount --block-device /dev/sda1
and in the end of the script I would like to unmount it.
However, it may ...
- 2,380
5
votes
1
answer
341
views
zsh - if condition comparison: '-ne' and '!=' have different result
Why these commands lead to opposite comparison results between -ne and !=? Seems != works but -ne does not? I thought they are the same while comparing strings.
% set -o | grep pipe
pipefail ...
- 632
0
votes
0
answers
30
views
dbus-send array:string fails with elements containing spaces [duplicate]
I am trying to run the following bash script:
#!/usr/bin/env bash
declare -A WM_CLASSES=(
["ALACRITTY"]="Alacritty"
["AUDACIOUS"]="Audacious"
[&...
- 3,134
1
vote
2
answers
54
views
Parent shell script blocked from exiting by background subshell
I have the following script flow:
The parent script is launched from a non-interactive shell and sources a child script.
child launches a background subshell with (...) & and contains no code ...
- 11
0
votes
1
answer
64
views
Bash Script Linux - combines a QUIET function with other functions without hiding some of them
#!/bin/bash
DefaultColor="\033[0m"
GREEN="\033[32m"
RED="\033[31m"
PURPLE="\033[35m"
YELLOW="\033[33m"
CYAN="\033[36m"
CmdOk="\033[...
- 3
0
votes
0
answers
34
views
LF file manager : how to go back to $OLDPWD?
What do I want :
On the file manager lf, we can bind some keyboard shortcuts to do either a lf command with :, or a shell command with $, !, or other symbols.
According to the documentation, there is ...
- 635
5
votes
1
answer
372
views
locking scripts using flock - can same file descriptor be used concurrently?
Common method for preventing concurrent runs for a given script is utilizing flock as:
LOCK=/var/lock/my-lock
exec 9>>"$LOCK"
if ! flock --exclusive --nonblock 9; then
echo "...
- 71
0
votes
0
answers
50
views
Sending SIGSTOP to background sleep process does not stop it; it keeps running
I am trying to implement a shell(zsh) based Pomodoro clock and I encountered a problem: sending -STOP signal to background sleep process does not stop it.
WesternGun@MyMacBook-Pro:~ [12:13:49] 0
% ...
- 632
1
vote
1
answer
56
views
Docker Container Mount Name, Type and other values
I am writing a bash script and I am aware that I can get information of the mounts attached to a container using docker inspect --format '{{.Mounts}}' <container-name> which gives a result such ...
- 133
0
votes
2
answers
88
views
What explains the measured overhead when timing a command in zsh?
When timing a command with time, there is inevitably some overhead (from the CPU, operating system, shell and so on).
Running the following code, from a tty text mode virtual console with all ...
- 209
6
votes
2
answers
281
views
Change some file names during a backup with rsync
I use a simple backup bash script to copy some directories originally placed in a Debian (Testing) from a USB stick (formatted NTFS) to a MacBook. The names of directories are the same from origin to ...
- 213
-4
votes
1
answer
227
views
How to redirect command output to a file if the command itself contains redirection
In the below shell script I'm executing the some command cmd remotely where in the command output is redirected to some file cmd_log. I'm getting the desired result as long as the command cmd itself ...
- 239
10
votes
4
answers
943
views
With `#!/bin/sh`, what is the closest to `;;&` (`bash`'s fallthrough)?
Without ;;&, /bin/sh gives Syntax error: ")" unexpected (expecting ";;").
;;& triggers shellcheck's ^-- SC2127 (error): To use cases with ;;&, specify #!/usr/bin/env ...
- 101
2
votes
1
answer
198
views
`printf` and `time` formatting issues in a `zsh` shell script
I have the following (excerpt from a) zsh shell script (the FOLDER environment variable is exported earlier in the code):
# Create temporary directory
export TMPDIR=$(mktemp -d)
# Set TIMEFMT to ...
- 209
0
votes
0
answers
75
views
A bash script problem installing Apache Cloudberry - it's a generic setup script - just isn't working for me
This is a fairly bog-standard script, but my bash knowledge isn't huge, so here goes.
The script is from here - the Apache Cloudberry project - an interesting open source version of a distributed ...
- 601
2
votes
4
answers
147
views
Is it possible to silence the initial call in xtrace, when BASH_XTRACEFD is set?
#!/usr/bin/env bash
exec {BASH_XTRACEFD}>./xtrace.log
declare -p BASH_XTRACEFD
set -x
{ : "how do you hide this in ./xtrace.log?"; } 2>/dev/null # fail
# { :; } "${BASH_XTRACEFD:-...
- 601
-2
votes
1
answer
128
views
extract fields of a string separated by |
In the below shell script I want to extract the fields of a string delimited by | character. But unfortunately I'm facing issue if there exists pipe command | in the string, because of which I'm not ...
- 239
1
vote
2
answers
339
views
get process id of a process running in remote machine
In the below shell script, I am trying to get the process id of a remote process using ps command, but not getting the required output
#!/bin/bash
get_process_id() {
local res
local ...
- 239
0
votes
5
answers
865
views
Extract email addresses from line, with multiple email addresses per line
I have a text file that mixes names and email addresses, in a comma-separated list.
First Person <[email protected]>, Second Person <[email protected]>, Third <[email protected]>
...
- 6,105
-4
votes
2
answers
277
views
Linux kill command returns "No such process"
In the below shell script I have list of process IDs which need to be killed. When killing a process I am getting kill: 1234567: no such process error even after checking if the process id existence ...
- 239
-3
votes
3
answers
139
views
How to pass an array as an argument to a function
In the below shell script I am passing an integer and a string array to a print function which should print each parameter separately, but I'm not able to. I don't want make a reference of passed ...
- 239
-2
votes
3
answers
159
views
Generate hashes automatically and continuously with a script and stop by pressing a key?
I need a part for a script in bash where hashes are generated automaticaly and continuously and when I press a key the generation stops and the last hash at which I stopped is displayed.
I've cobbled ...
- 65
1
vote
2
answers
128
views
How to pass an argument by reference to a function in KornShell (PDKSH 5.2.14)
In bash I can use
local -n ref_name=$1
to pass an argument to a function by reference, but the same syntax in ksh throws an error saying
typeset: -n: unknown option
I tried nameref ref_name=$1 ...
- 239
1
vote
2
answers
240
views
Check if a given function name exists in a sourced shell script file
In Bash I can use $(type -t function_name) = "function" to check if the function by name function_name exists or not in a sourced file which is sourced using source file_name command. I'm ...
- 239
1
vote
1
answer
80
views
List all the directories residing in a directory path using KornShell
I have the below shell script which works fine in Bash to list all the directories residing inside a given directory path and add them to an array. But the same script code doesn't work in KornShell.
...
- 239
13
votes
1
answer
2k
views
Shebang apparently calls wrong shell
I am currently relearning a few basics about shell scripts and encountered the following problem.
I have the following script error.sh
#!/usr/bin/env bash
n=$(( RANDOM % 100 ))
if [[ n -eq 42 ]]; ...
- 233
0
votes
0
answers
83
views
Why mount a directory to itself. mark it make-rshared and mount option inside a container
I’m using BTRFS snapshots for my backups with Restic, and with the help of GenAI I created a script to automate the process. I take snapshots of a subvolume called home, which contains three ...
- 103
1
vote
1
answer
172
views
Execute a script at startup as a root that executes a software an keep it running
If executed manually with sudo, the script does its job.
#!/bin/bash
echo "Script executed at $(date)" >> /var/log/realtimesync.log
echo
/opt/FreeFileSync/RealTimeSync /mnt/harddrive/...
- 407
4
votes
4
answers
838
views
How to check if a path exists from a string with case insensitive?
Hello i try to check if a path exists with a if statetment in a bash script from a string. I try the follow but nothing seems to handle this.
The path is /home/orhan/Blog/Mai1
path='/home/orhan/blog/...
- 65
2
votes
2
answers
386
views
Can I execute multiple case blocks if the pattern matches?
I want to know if there is another alternative in Bash to execute multiple blocks when the pattern matches.
I don’t want to use another command, if statements, or two or more separate case blocks or ...
- 10.1k
4
votes
4
answers
546
views
How to wait for background commands that were executed within a subshell?
Given this code:
#!/bin/bash
set -euo pipefail
function someFn() {
local input_string="$1"
echo "$input_string start"
sleep 3
echo "$input_string end"
}
function ...
- 16.7k
5
votes
4
answers
516
views
Creating n folders with equal number of files from a large folder with all files
I have a large folder of data files, which I want to copy into subfolders to make a specified number of batches.
Right now I count how many files there are and use that to make ranges, like so:
cd /...
- 63
10
votes
7
answers
1k
views
Check if multiple files exist on a remote server
I am writing a script that locates a special type of file on my system and I want to check if those files are also present on a remote machine.
So to test a single file I use:
ssh -T user@host [[ -f /...
- 203
-2
votes
2
answers
102
views
HISTTIMEFORMAT not working as desired in RHEL 8 bash 4.4.20
so trying to capture history with date and readable timestamps AND the command should appear on same line. following is failing:
Bash ver is: GNU bash, version 4.4.20(1)-release (x86_64-redhat-linux-...
- 268
2
votes
1
answer
170
views
Semicolon in conditional structures after the closing double bracket in a bash/zsh script?
Continuing Semicolon in conditional structures (which handles single brackets), what's the point of having a semicolon after the closing DOUBLE bracket ]]?
In my tests, running
#!/bin/zsh --
if [[ &...
- 1
1
vote
1
answer
100
views
Process some Folders and format the output
In Linux there are some Folders.
I want to process each of this Folders with the program myprogramm.
I get a list with ls -1 or much better, sure only Folders with:
find . -maxdepth 1 -type d -printf '...
- 241
1
vote
0
answers
68
views
How to send an email with an attachment, but so that the attachment is not saved on the mail server
I send emails from the terminal with mutt -s "This is Subject" -a a.txt -- [email protected] < test.txt. The a.txt attachments can be large, how can I avoid filling up the mail server?
...
- 33
2
votes
1
answer
119
views
Sending emails from the Linux terminal while preserving the fact of sending
I need to send a letter from Linux terminal to the recipient's mailing address. I want the fact of sending the letter, its title and its text to be saved in the sent section of my mailbox (the mailbox ...
- 33
5
votes
2
answers
846
views
What does VAR=() mean in a script?
In the file /usr/bin/gcore (which is a bash script on my system), there are the following lines:
# When the -a option is present, this may hold additional commands
# to ensure gdb dumps all mappings (...
- 454
0
votes
2
answers
312
views
I have tried to install Howdy (practically Linux's Windows Hello). However, it seems like pypy3 failed to execute or something
I have tried to install Howdy, but it would always return with this message:
>>> Upgrading pip to the latest version
error: externally-managed-environment
× This environment is externally ...
0
votes
5
answers
213
views
Rename a set of files according to a specific scheme, with rename back option
In Linux in a directory there are files, ls -1 shows me this output :
file1.1-rvr
file1.2-rvr
file1.3
file1.4-rvr
file1.5
file1.6-rvr
file2.1
file2.2
file3.1
file3.10
file3.2-rvr
file3.3-rvr
file3.4
...
- 241
4
votes
0
answers
122
views
Recovering text of Unsaved document from process memory? (frozen Xed window - process still "running" but in Sleeping status)
The window of my text editor Xed froze with Unsaved documents just as I was doing 'File'->'Save as...' to save them... [How ironic.]
Since the process still exists, I am trying to recover the text ...
- 454
6
votes
1
answer
263
views
bash & zsh friendly process substitution
In bash I'm using this common pattern where null-terminated list of process output is processed in a loop, e.g.
declare -a commits
while IFS= read -r -d $'\0' c; do
commits+=("${c%% *}")
...
- 804