314
votes
Accepted
How to append tee to a file in Bash?
echo -e "First Line" | tee ~/output.log
echo -e "Second Line" | tee -a ~/output.log
^^
From man tee:
Copy standard input to each FILE, and also to standard output.
...
- 4,877
309
votes
Why does "(base)" appear in front of my terminal prompt?
This can also be because auto_activate_base is set to True. You can check this using the following command
conda config --show | grep auto_activate_base
To set it false
conda config --set ...
- 3,191
228
votes
Accepted
How do I show the git branch with colours in Bash prompt?
This snippet:
# Add git branch if its present to PS1
parse_git_branch() {
git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/(\1)/'
}
if [ "$color_prompt" = yes ]; then
PS1='${...
- 35.9k
208
votes
How do I show the git branch with colours in Bash prompt?
Ubuntu: Show your branch name on your terminal
Add these lines in your ~/.bashrc file
# Show git branch name
force_color_prompt=yes
color_prompt=yes
parse_git_branch() {
git branch 2> /dev/null | ...
- 2,189
188
votes
Accepted
How to change Windows line-ending to Unix version
Option 1: dos2unix
You can use the program dos2unix, which is specifically designed for this:
dos2unix file.txt
will replace all CR from all lines, in place operation.
To save the output in a ...
- 91.8k
176
votes
Make Command Not Found
Run this command to install make and all the packages needed to build your code.
sudo apt-get install build-essential
- 1,863
144
votes
Accepted
What is the meaning of exit 0, exit 1, and exit 2 in a bash script?
Here's one good reference for shell exit codes:
Exit code 0 Success
Exit code 1 General errors, Miscellaneous errors, such as "divide by zero" and other impermissible operations
Exit ...
- 62.3k
132
votes
Accepted
What is the point of sh being linked to dash?
The short answer to “why the original sh shell isn't present in sh” is that there's no original sh.
Well, ok, there is: it's the Thompson shell. Version 1 had some of the features we know today, in ...
124
votes
Accepted
Why does "(base)" appear in front of my terminal prompt?
This appears to come from your conda environment. In particular, you are activating conda from your ~/.bashrc as follows
# added by Anaconda3 installer
#export PATH="/home/jim/anaconda3/bin:$PATH"
. /...
- 136k
122
votes
Accepted
What does $# mean in bash?
$# is a special variable in bash, that expands to the number of arguments (positional parameters) i.e. $1, $2 ... passed to the script in question or the shell in case of argument directly passed to ...
- 91.8k
121
votes
How to make LV use all disk space in PV?
I also used the default Ubuntu 20.04 install from ISO w/ lvm option selected. I had the same problem with the OS disk not occupying what I had allocated. Eddie's suggestion and the provided link did ...
- 1,311
110
votes
How to pass an array as function argument?
If you want to pass one or more arguments AND an array, I propose this change to the script of @A.B.
Array should be the last argument and only one array can be passed
#!/bin/bash
function copyFiles()...
- 1,201
109
votes
Accepted
What command is the alias ll for?
You can use the alias or type commands to check what a specific alias means:
$ alias ll
alias ll='ls -alF'
$ type ll
ll is aliased to `ls -alF'
Note however that aliases might use other aliases, so ...
- 108k
103
votes
How do I fix "$'\r': command not found" errors running Bash scripts in WSL?
Inside WSL:
sudo apt-get install dos2unix
Then,
dos2unix [file]
Full documentation:
man dos2unix
Saved my day, hope it helps.
- 1,169
101
votes
Script to display all terminal colors
A simple one-liner that should work for most people.
msgcat --color=test
- 1,119
101
votes
Accepted
How to display modification time of a file?
Don't use ls, this is a job for stat:
stat -c '%y' filename
-c lets us to get specific output, here %y will get us the last modified time of the file in human readable format. To get time in seconds ...
- 91.8k
98
votes
Accepted
Differentiate Interactive login and non-interactive non-login shell
The only real misconception you seem to have is about what constitutes a non-interactive, login shell.
Briefly (see here for more details), with examples:
interactive login shell: You log into a ...
- 101k
97
votes
Accepted
Why is there a /bin/echo and why would I want to use it?
If you open up a bash prompt and type in an echo command, that uses a shell builtin rather than running /bin/echo. The reasons it is still important for /bin/echo to exist are:
You're not always ...
- 118k
92
votes
Accepted
How can I sum numbers on lines in a file
bc with a little help from paste to get the lines in a single one with + as the separator:
paste -sd+ file.txt | bc
To use the output of grep (or any other command) instead a static file, pass the ...
- 91.8k
89
votes
Accepted
Best way to read a config file in bash
As mbiber said, source another file. For example, your config file (say some.config) would be:
var1=val1
var2=val2
And your script could look like:
#! /bin/bash
# Optionally, set default values
# ...
- 198k
87
votes
Accepted
What does grep -v "grep" mean and do?
grep -v "grep" takes input line by line, and outputs only the lines in which grep does not appear. Without -v, it would output only the lines in which grep does appear. See man grep for details.
As ...
- 118k
86
votes
Accepted
Why can't I cd to a quoted tilde ('~')?
As @karel noted in his answer, ~ is a special character and expanded by Bash into the current user's home directory. See Bash's manual on "Tilde Expansion", or search for the headline "Tilde Expansion"...
- 108k
79
votes
Accepted
What does this syntax mean?
$ type echo
echo is a shell builtin
meaning, the echo command is part of the bash program itself (assuming you use bash)
-n is an option, so let's see what it does
$ help echo
Write arguments to ...
- 70.5k
73
votes
Accepted
Request root privilege from within a script
This'll work:
echo "$(whoami)"
[ "$UID" -eq 0 ] || exec sudo "$0" "$@"
example:
./test.sh
blade
[sudo] password for blade:
root
- 26.7k
71
votes
Accepted
How can I run OpenVPN as root in the background, in a script?
TL;DR: Use sudo -b or, better, openvpn [...] --daemon.
Since you're running openvpn (and, less specifically, since you wish to run a program as root in the background), the most commonly dispensed ...
- 118k
68
votes
Accepted
How to check computer's timezone through Terminal?
Use:
timedatectl status | grep "Time zone"
Without the grep you get a lot more of information.
As pointed out by @Christian Ulbrich in comment the wording for timezone seems to change depending on ...
- 33.4k
68
votes
Create alias for ssh connecting
Use the intended way and write the options and aliases into ~/.ssh/config:
Host 1
Port 12345
User my_user
HostName 123.123.123.1
Host 2
Port 12345
User my_user
HostName 123.123.123.2
...
- 6,615
64
votes
Accepted
Is there a way reverse of what mkdir -p option does?
The reversal of the mkdir -p command would be rmdir -p. rmdir -p will remove the folder structure up till the folder is not empty. You should be able to use rmdir instead of mkdir on your command:
...
- 41.7k
63
votes
Accepted
Is it possible to stop .sudo_as_admin_successful being created?
Based on the following section of the plugins/sudoers/sudoers.c source code file, it doesn't look like it's possible without recompiling sudo, undefining the USE_ADMIN_FLAG pre-processor macro.
Also, ...
- 136k
63
votes
Accepted
How do I split a "/proc/*/environ" file in separate lines?
The entries are separated by the null character, see man 5 proc:
/proc/[pid]/environ
This file contains the environment for the process. The entries
are separated by null bytes ('\0'), ...
- 198k
Only top scored, non community-wiki answers of a minimum length are eligible