Questions tagged [bash]
Bash is a free shell for Unix-like operating systems from the GNU Project.
11,762
questions
798
votes
13
answers
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What does 'source' do?
$ whatis source
source: nothing appropriate.
$ man source
No manual entry for source
$ source
bash: source: filename argument required
source: usage: source filename [arguments]
It exists, and it is ...
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568
votes
6
answers
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Difference between .bashrc and .bash_profile
What's the difference between .bashrc and .bash_profile and which one should I use?
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495
votes
11
answers
1.3m
views
What is the home directory on Windows Subsystem for Linux?
When I start bash on Windows Subsystem for Linux, it drops me in the directory
/mnt/c/Users/<username>
When I ls this directory, I see the directories Desktop, Documents, etc. that I can see ...
- 5,093
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votes
7
answers
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views
What is the difference between executing a Bash script vs sourcing it?
What is the difference between executing a Bash script like A and sourcing a Bash script like B?
A
> ./myscript
B
> source myscript
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votes
11
answers
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How do I add text to the beginning of a file in Bash?
Hi I want to prepend text to a file. For example I want to add tasks to the beginning of a todo.txt file. I am aware of echo 'task goes here' >> todo.txt but that adds the line to the end of ...
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votes
19
answers
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How to encode base64 via command line in macOS/OS X?
Is there a terminal command in macOS/OS X which will base64 encode a file or stdin?
- 9,797
402
votes
21
answers
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views
How do I detach a process from Terminal, entirely?
I use Tilda (drop-down terminal) on Ubuntu as my "command central" - pretty much the way others might use GNOME Do, Quicksilver or Launchy.
However, I'm struggling with how to completely detach a ...
AnC
397
votes
13
answers
287k
views
How can I search the bash history and rerun a command?
Can I search history in bash and run the result?
- 12.6k
390
votes
4
answers
680k
views
Go back to previous directory in shell
Is there a way to go back to previous directory we were in using bash,tcsh without using pushd/popd ?
I'd like to type something like "back" and got returned to the previous directory I was in.
Edit:
...
- 6,029
387
votes
5
answers
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views
Bash: Iterating over lines in a variable
How does one properly iterate over lines in bash either in a variable, or from the output of a command? Simply setting the IFS variable to a new line works for the output of a command but not when ...
- 4,032
372
votes
10
answers
383k
views
chown is not changing symbolic link
I'm trying to change the user/group of a symbolic link with the command:
$ chown -h myuser:mygroup mysymbolic/
But it's not changing. I'm logged in as root. The current user/group is set to root:...
rizidoro
258
votes
5
answers
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views
Linux Bash Script, Single Command But Multiple Lines?
I have the following script I wrote by searching Google, and it backs up my Linux system to an archive:
#!/bin/bash
# init
DATE=$(date +20%y%m%d)
tar -cvpzf /share/Recovery/Snapshots/$HOSTNAME_$...
- 2,601
249
votes
11
answers
371k
views
What to do when Ctrl + C can't kill a process?
Ctrl + C doesn't always work to kill the current process (for instance, if that process is busy in certain network operations). In that case, you just see "^C" by your cursor and can't do ...
- 2,601
242
votes
6
answers
156k
views
In bash, how do I escape an exclamation mark?
I want to do something like bzr commit -m "It works!". I can sort of escape the exclamation mark by doing bzr commit -m "It works\!". However, then my commit message includes the backslash. How do I ...
- 14.8k
236
votes
3
answers
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views
What does the 'rc' in `.bashrc`, etc. mean? [duplicate]
Well, this is embarrassing. I feel like I just realised I don't know a loyal colleague's name after working with them for 10 years. "Hey, er... *cough!*, thanks for that great job you did on setting ...
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225
votes
26
answers
292k
views
Bash scripting: test for empty directory
I want to test if a directory doesn't contain any files. If so, I will skip some processing.
I tried the following:
if [ ./* == "./*" ]; then
echo "No new file"
exit 1
fi
That gives the ...
- 5,068
225
votes
4
answers
57k
views
Using watch with pipes
I'd like to run this command:
watch -n 1 tail -n 200 log/site_dev.log | grep Doctrine
But it does not run, because "I think" that the grep tries to run on the watch instead of the tail...
Is there ...
- 2,599
225
votes
5
answers
225k
views
How to ignore certain filenames using "find"?
One of my favorite BASH commands is:
find . -name '*.*' -exec grep 'SearchString' {} /dev/null \;
which searches the contents of all of the files at and below the current directory for the specified ...
- 2,514
220
votes
7
answers
297k
views
Why does Ctrl + V not paste in Bash (Linux shell)?
When I copy something to the clipboard and press Ctrl + V in Bash, nothing happens; However, right clicking and selecting Paste does the job.
Why? Is there any reasonable issue (I'm sure there is) ...
- 2,687
218
votes
9
answers
312k
views
How can I find only the executable files under a certain directory in Linux?
How can I find only the executable files under a certain directory in Linux?
- 4,057
206
votes
11
answers
41k
views
I accidentally typed password into bash command line
I accidentally typed my password into bash command line, mistaking the Last login: ... line for Wrong password (I was in a hurry). What do I do to cover my trace?
What I did was editing .bash_history ...
- 2,013
203
votes
8
answers
216k
views
Execute a command from another directory in bash
Say that I'm doing this:
cd subdir
git init
cd ../
Is there a way to do this with a single command, or perhaps two, rather than having to move in and out of a directory in order to run a command ...
- 2,441
202
votes
2
answers
343k
views
How to access Windows folders from Bash on Ubuntu on Windows
On the Bash on Ubuntu on Windows app, I only have
root@localhost:~# ls -a
.bash_history .bashrc .profile
How do I access all of the Windows folders like Documents, Downloads, etc.?
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198
votes
15
answers
216k
views
Is it possible to `tail -f` the output of `dmesg`?
I want to do something like
dmesg | tail -f
but it doesn't work:
I use Mac OS X v10.6.7 (Snow Leopard). By doing that, tail will exit, instead of monitoring the output.
I wonder if there is a ...
- 2,825
179
votes
12
answers
182k
views
Remove a certain line from Bash history file
How can I remove a certain line from history's database?
- 2,993
179
votes
23
answers
67k
views
Add directory to $PATH if it's not already there
Has anybody written a bash function to add a directory to $PATH only if it's not already there?
I typically add to PATH using something like:
export PATH=/usr/local/mysql/bin:$PATH
If I construct ...
- 28k
168
votes
4
answers
117k
views
How to use spaces in a bash alias name?
I am trying to create an aliases in bash. What I want to do is map ls -la to ls -la | more
In my .bashrc file this is what I attempted:
alias 'ls -la'='ls -la | more'
However it does not work ...
- 8,279
165
votes
3
answers
50k
views
Case insensitive tab completion in Bash
Is there any way to make Bash tab complete case insensitively?
$ bash --version
GNU bash, version 3.2.48(1)-release (x86_64-apple-darwin10.0)
Copyright (C) 2007 Free Software Foundation, Inc.
I am ...
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163
votes
9
answers
527k
views
looping through `ls` results in bash shell script
Does any one have a template shell script for doing something with ls for a list of directory names and looping through each one and doing something?
I'm planning to do ls -1d */ to get the list of ...
- 4,108
162
votes
10
answers
226k
views
How can I do a recursive find and replace from the command line?
Using a shell like bash or zshell, how can I do a recursive 'find and replace'? In other words, I want to replace every occurrence of 'foo' with 'bar' in all files in this directory and its ...
- 26.8k
156
votes
8
answers
258k
views
Windows Linux Subsystem - Accessing Files outside of Ubuntu
Why, when I create a file from within Windows for example,
can I not see it under the Linux sub system in Windows 10 (bash.exe)
The screenshot should explain.
Folder: OMG was created from within ...
- 1,701
152
votes
8
answers
139k
views
How to configure PuTTY so that Home/End/PgUp/PgDn work properly in bash?
The keys Home, End, PageUp, PageDown all type a ~ in my bash session instead of moving the cursor / view around. Why does this happen and which settings do I need to change?
GNU bash, version 4.0.28(...
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votes
9
answers
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views
How do I make Bash my default shell on Ubuntu?
I have a .bash_profile in my home directory, but it isn't getting run on login. If I do the following, then things seem to be as I expect:
ssh myhost
bash
source ~/.bash_profile
But normally that ...
- 2,282
151
votes
3
answers
202k
views
What does export do in BASH? [duplicate]
Possible Duplicate:
Difference between “a=b” and “export a=b” in bash
It is hard to admit, but I have never really understood what exactly export does to an environment ...
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votes
4
answers
241k
views
Display each sub-directory size in a list format using one line command in Bash?
I want to get a list of the directories and their sizes in a list format like how you get when you do a ls -l.
The thing is that is there a one line command that can do this? I see others have long ...
- 3,039
150
votes
4
answers
254k
views
Bash if on single line
I would like to know how can I write if conditions inside a bash script on a single line.
For example, how can I write this on a single line, and then put another one just like it on the next?
if [ -...
- 1,651
149
votes
6
answers
258k
views
How to prevent SSH from disconnecting if it's been idle for a while
I have a ssh connection to a machine which gets disconnected by that machine after 30 minutes of no user input. However, if I start something like top, the connection stays alive.
Since this is a ...
- 1,904
145
votes
8
answers
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views
Where does $PATH get set in OS X 10.6 Snow Leopard?
I type echo $PATH on the command line and get
/opt/local/bin:/opt/local/sbin:/Users/andrew/bin:/usr/local/bin:/usr/local/mysql/bin:/usr/local/pear/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/...
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votes
6
answers
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Does bash have a hook that is run before executing a command?
In bash, can I arrange for a function to be executed just before running a command?
There is $PROMPT_COMMAND, which is executed before showing a prompt, i.e., just after running a command.
Bash's $...
140
votes
7
answers
301k
views
Get home directory by username
I want to obtain home dir of any user with echo
echo ~puchuu
>> /home/puchuu
But I cant use variable
echo ~$USER
>> ~puchuu
echo `echo ~$USER`
>> ~puchuu
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votes
3
answers
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Where is the C drive in the WSL? [duplicate]
Whenever I try to login to bash using the Windows Subsystem for Linux, I try to cd into C:\Users\, but all I get is directory not found.
Where is the C drive for the Windows Linux subsystem? Is it ...
- 2,901
139
votes
8
answers
186k
views
Show only current directory name (not full path) on bash prompt
The way my bash prompt is currently configured, it shows the whole path to the current directory. This is annoying when I'm deep inside a directory tree, as the prompt becomes so long that every ...
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votes
6
answers
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How do I reload .inputrc?
Background
I have heard that the readline module is reading ~/.inputrc and that is how it changes the behaviour of keystrokes under programs such as bash.
Question
How can I reload this after ...
- 1,960
133
votes
8
answers
1.1m
views
How can I resolve the error "cannot execute binary file"?
When I login using SSH, all I can see is this...
-bash: /usr/bin/id: cannot execute binary file
-bash: [: : integer expression expected
I couldn't do anything in here. Commands such as halt, ...
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132
votes
18
answers
55k
views
Substitution in text file **without** regular expressions
I need to substitute some text inside a text file with a replacement. Usually I would do something like
sed -i 's/text/replacement/g' path/to/the/file
The problem is that both text and replacement ...
- 1,525
131
votes
17
answers
179k
views
How to delete all files in a directory except some?
I need to delete all files in a directory, but exclude some of them. For example, in a directory with the files a b c ... z, I need to delete all except for u and p. Is there an easy way to do this?
- 1,449
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votes
2
answers
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How to add a mp3 handler to sox?
I want to play music in the terminal with sox.
# install sox/lame
sudo apt-get install sox
sudo apt-get install lame
# play music
play music.mp3
# play FAIL formats: no handler for file extension `...
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130
votes
7
answers
38k
views
How can I save the current contents of less to a file?
If I've piped the results of a command to less and then decided that I want to save the contents to a file, is this possible?
I've tried setting a mark a at the end of the buffer, and then returning ...
- 1,611
130
votes
3
answers
43k
views
How do I unset or get rid of a bash function?
If you set or export an environment variable in bash, you can unset it. If you set an alias in bash, you can unalias it. But there doesn't seem to be an unfunction.
Consider this (trivial) bash ...
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129
votes
5
answers
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views
Finding files which contain a certain string using find (1) and grep (1)
find . -type f -print -exec cat {} \; | grep some string
Command above doesn't print the file path.
I'm using: Ubuntu, bash 4.
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