Questions tagged [scripts]
A script is a program or sequence of instructions written in a plain text file. The script interpreter (for example Bash, Python, Perl etc.) reads the file and carries out the instructions as if they had been entered at the command prompt. Use this tag for all questions related to creating, troubleshooting and running scripts.
6,699
questions
501
votes
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answers
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How do I run .sh scripts?
Whenever I open a .sh file, it opens it in gedit instead of the terminal. I can't find any option similar to Right Click → Open With → Other Application... → Terminal.
How do I open this file in the ...
477
votes
2
answers
379k
views
Differences between /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin, /usr/local/sbin
I have six directories with command files. These are /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin and /usr/local/sbin.
What are the differences between these? If I'm writing my own scripts, where ...
416
votes
4
answers
873k
views
What is the difference between #!/bin/sh and #!/bin/bash?
if I write,
#!/bin/bash
echo "foo"
or
#!/bin/sh
echo "foo"
both yields same. I have seen some scripts starting with #!/bin/sh or #!/bin/bash. Is there any difference between them?
381
votes
16
answers
730k
views
How can I get a list of all repositories and PPAs from the command line into an install script?
I know how to list all packages installed on my system.
But how could I get a list of all repositories and PPA's into a script that I can run on a new machine to replicate the repository setup ...
300
votes
7
answers
441k
views
ssh: automatically accept keys
I've written this small utility script:
for h in $SERVER_LIST; do ssh $h "uptime"; done
When a new server is added to $SERVER_LIST, the script is stopped with:
The authenticity of host 'blah.blah....
231
votes
8
answers
745k
views
How can I make a script that opens terminal windows and executes commands in them?
I have three scripts I need to run when I start up my Ubuntu machine, they start services I use in my development environment.
To do that, I manually open three terminals and type in the commands.
...
210
votes
7
answers
415k
views
How to read complete line in 'for' loop with spaces
I am trying to run a for loop for file and I want to display whole line.
But instead its displaying last word only. I want the complete line.
for j in `cat ./file_wget_med`
do
echo $j
done
result ...
209
votes
11
answers
728k
views
How can I create a select menu in a shell script?
I'm creating a simple bash script and I want to create a select menu in it, like this:
$./script
echo "Choose your option:"
1) Option 1
2) Option 2
3) Option 3
4) Quit
And according to ...
206
votes
8
answers
682k
views
Not able to execute a .sh file: /bin/bash^M: bad interpreter
I wanted to execute a shell script:
-rwxr-x--x 1 root root 17234 Jun 6 18:31 create_mgw_3shelf_6xIPNI1P.sh
I tried to do a standard procedure, but I got this error:
./create_mgw_3shelf_6xIPNI1P....
198
votes
11
answers
369k
views
How to run an alias in a shell script?
I have an executable file mpiexec, whose full path is ~/petsc-3.2-p6/petsc-arch/bin/mpiexec. Since I want to execute this command in different directories (without having to retype the entire path), ...
197
votes
3
answers
524k
views
Command to append line to a text file without opening an editor
Assuming i have a line that i want to add to a file without opening an editor.
How could i append this line
alias list='ls -cl --group-directories-first'
to this file
config.fish
191
votes
8
answers
368k
views
Repeat a command every x interval of time in terminal?
How can I repeat a command every interval of time , so that it will allow me to run commands for checking or monitoring directories ?
There is no need for a script, i need just a simple command ...
171
votes
2
answers
67k
views
What is the difference between "source" and "."?
What is the difference between executing a script (e.g. /some/script) with source /some/script and . /some/script in Bash?
170
votes
11
answers
186k
views
How can a script check if it's being run as root?
I'm writing a simple bash script, but I need it to check whether it's being run as root or not. I know there's probably a very simple way to do that, but I have no idea how.
Just to be clear:
What's ...
167
votes
5
answers
561k
views
'chmod u+x' versus 'chmod +x'
What is the difference between chmod u+x and just chmod +x? I have seen a ton of tutorials that say to use u+x to make scripts executable. However, omitting the u doesn't seem to have any effect.
166
votes
2
answers
211k
views
What does outputting to /dev/null accomplish in bash scripts? [duplicate]
Oftentimes I run into small bash scripts that use this sort of syntax in if statements:
some command > /dev/null 2>&1
What is the purpose of outputting to /dev/null like that, and what does the 2>...
159
votes
13
answers
372k
views
How to execute a script just by double clicking like .EXE files in Windows?
How can I make a bash script executable by double clicking just like .exe files in Windows? I tried creating a launcher and assigning the script to it, but there are two consequences:
the terminal ...
152
votes
7
answers
630k
views
How do I run a 'sudo' command inside a script?
To do a patch manually I must type this command
sudo ./playback_delete_data_patch.sh 09_delete_old_data_p.sql
There is a space just before the 09:
sudo ./playback_delete_data_patch.sh [space] ...
141
votes
2
answers
324k
views
How to add a shell script to launcher as shortcut [duplicate]
Possible Duplicate:
How can I edit/create new launcher items in Unity by hand?
How can I create launchers on my desktop?
I want to add some shell scripts in my launcher as shortcuts..
They are ...
139
votes
5
answers
542k
views
How do I run a script at start up? [duplicate]
I have a script in a folder:
/path/to/my/script.sh
I need this script to run every time the system starts (even if no one logs in to the system). What do I need to do in order to make this happen?
133
votes
10
answers
395k
views
Bash remove first and last characters from a string
I have a string like that:
|abcdefg|
And I want to get a new string called in someway (like string2) with the original string without the two | characters at the start and at the end of it so that I ...
130
votes
13
answers
173k
views
Script to display all terminal colors
Throughout the internet I have seen many people with scripts that prints out a bunch of stuff in all the colors defined in ~/.Xdefaults. However when I try to use these, I always get error: Bad ...
123
votes
4
answers
555k
views
What is the meaning of exit 0, exit 1, and exit 2 in a bash script?
I'm doing some practice exercises.
Write a script that will be given a month number as the argument and will translate this number into a month name. The result will be printed to stdout.
I made a ...
113
votes
5
answers
177k
views
Is there a standard place for placing custom Linux scripts? [duplicate]
I am developing a set of scripts, which I want to be present for all users, when I set up a server. But I don't want them in the standard locations like /usr[/local]/[bin],[sbin] etc.
Is there some ...
109
votes
12
answers
500k
views
How do I read a variable from a file?
I want to insert in my script a value (string) that I would read from a text file.
For example, instead of:
echo "Enter your name"
read name
I want to read a string from another text file so the ...
107
votes
17
answers
152k
views
Beep in shell script not working?
I'd like to use a beep sound in a shell script. Unfortunately none of the methods I found via Google work for me.
I tried
echo -e '\a'
echo -ne '\007'
and the command beep after I installed it via ...
105
votes
5
answers
427k
views
How to run a shell script in background?
How can I run a shell script in background?
101
votes
4
answers
513k
views
How can I make /etc/rc.local run on startup?
I have a script I would like to run when my system starts and have put it in /etc/rc.local, but it doesn't work. How can I enable it to run on startup?
97
votes
5
answers
150k
views
How to do: underline, bold, italic, strikethrough, color, background, and size in Gnome Terminal?
How to do: underline, bold, italic, strikethrough, and color in Gnome Terminal?
Bold
Italic
u̲n̲d̲e̲r̲l̲i̲n̲e̲
s̶t̶r̶i̶k̶e̶ ̶i̶t̶ ̶l̶i̶k̶̶e̶ ̶i̶t̶s̶ ̶h̶o̶t
Color
background
font < (its mono if you ...
96
votes
4
answers
252k
views
Error message 'source: not found' when running a script
I am creating a little automated setup script that will modify /etc/profile and $HOME/.profile if some paths are not exported. Then, I'd like to reload these automatically.
I have read that source ...
95
votes
4
answers
424k
views
How to execute a script in a different directory than the current one?
I tried executing a script with this command:
./home/user/scripts/someScript
but it doesn't work:
No such file or directory
Any ideas?
95
votes
5
answers
73k
views
When to use () vs. {} in bash?
I'm studying shell scripting with bash and I need to know the difference between (...) and {...}. How does one select between the two when writing a script?
94
votes
3
answers
840k
views
What does "chmod +x <filename>" do and how do I use it?
I want to write the Ubuntu analogue of a "batch file" (a shell script). But I don't know how to use chmod +x filename command to make it so that the script can be run. Nor do I know where to use it.
90
votes
8
answers
52k
views
How do I create a deb package for a single python script?
I have a single python script that I want to distribute as a deb package. It is a indicator which shows local date in Unity panel. I did follow create a .deb Package from scripts or binaries but I ...
87
votes
8
answers
274k
views
How to run a script during boot as root
I had a script that automatically enables my wifi without using networkmanager, but I don't know how to run the script as root while the system is booting. How do I make the script run automatically ...
85
votes
5
answers
119k
views
Is bash scripting the same as shell scripting?
I'm very new to Ubuntu. I hear people say "shell scripting", "bash scripting".
I wonder are they same? Or they are different?
85
votes
1
answer
53k
views
How do I add a PPA in a shell script without user input?
Basically, I want to run add-apt-repository ppa:(whatever) without the "press Enter to continue" prompt. How would I do this?
Essentially, I want to deploy adding a repository in a shell script ...
84
votes
8
answers
439k
views
How to run scripts every 5 seconds?
I have a script that needs to be run every five seconds. I know that cron can do tasks by the minute, but is there a way to run something every second?
84
votes
3
answers
84k
views
Displaying a new line on the prompt
I wish to add a new line on every prompt. Instead of the cursor showing on the line as
name@machine:~$ _,
I want it to be on the next line, like as:
name@machine:~$
_
Thanks.
84
votes
6
answers
136k
views
Cannot successfully source .bashrc from a shell script
Normally we can source ~/.bashrc file using this command
source ~/.bashrc
but if I write this in a shell script and execute it, nothing happens. Why?
Is there any way to do this?
My script:
#!/bin/...
84
votes
4
answers
40k
views
Should I save my scripts with the .sh extension?
I have some functional scripts and I want to copy to /usr/bin I want to use them as normal terminal commands. Is it a good practice to use them with the .sh extension or can I save them without ...
82
votes
3
answers
124k
views
Where should I put my script so that I can run it by a direct command? [duplicate]
Where can (should) I put my (bash) script so that it can be used (forever) by terminal or by a direct command: Alt+F2?
I know there is /usr/bin and /sbin & /bindirectories but when should I use ...
82
votes
6
answers
61k
views
What is the difference between ./ and sh to run a script?
I have written a simple script.
When I runsh <myscriptname.sh>, i got the correct output, but when I run ./<myscriptname.sh>, I got an error.
What is difference between when I do sh and ....
79
votes
3
answers
212k
views
Hiding output of a command
I have a script where it checks whether a package is installed or not and whether the port 8080 is being used by a particular process or not. I am not experienced at all with bash, so I did something ...
79
votes
1
answer
519k
views
HTTP POST and GET using cURL in linux
I had server application in asp.net in windows in that i had a web service for that .
how can i call web service in ubuntu using shell script by using cURL command
76
votes
9
answers
108k
views
Rotate images from terminal
I have a directory with a lots of images but they are in the wrong orientation. I want to rotate the images to correct the orientation (mostly ±90o). Using image (shotwell photo) viewer I can ...
76
votes
2
answers
17k
views
Can I make the webcam take a picture when an incorrect password is entered?
I am using a laptop . I was thinking to have a support in my Ubuntu machine. When an incorrect password is entered, a picture is taken later revealing who has been trying to gain access.
I have ...
74
votes
5
answers
248k
views
how to check if $1 and $2 are null?
I am running some script which passing the string argument and I want to do if else statement shown as below:
if [ $1 != '' ] && [ $2 != '' ]
then
do something.....
but it shown Error ...
73
votes
10
answers
119k
views
How to run scripts without typing the full path?
I'd like to know if there is a way to run program/shell script without typing full path:
/opt/idea/bin/idea.sh
73
votes
4
answers
39k
views
Is #!/bin/sh read by the interpreter?
In bash or sh, I guess anything which starts with # is a comment.
But in bash scripts we write:
#!/bin/bash
And in Python scripts, there is:
#!/bin/python
Does this mean that # by itself is a ...