Bash is the shell from the GNU project. It is the standard shell on many Linux distributions and often available on other *NIXes.
-1
votes
4answers
80 views
Ending Process Infinite Loop Input Redirection
Edit: I realized that the program I was trying to run had an infinite loop after scanning all my input. Then just prints out infinitely so it'll never read the EOF. It'll read the last input then go ...
2
votes
2answers
64 views
Including sub-parameters in help options to execute wisely without getopt or getopts?
I am writing a script which can choose a file and print specific content. For example,
san#./script.sh
Expected Usage : ./script.sh --file1 --dns
(Here it checks for file1, search for dns name and ...
1
vote
1answer
61 views
How to open process substituted file from php?
Here's what I tried to do myself:
$ type 1.sh
#!/bin/bash -eu
php -r 'var_dump(file_get_contents($_SERVER["argv"][1]));' -- <(echo 1)
$ ./1.sh
PHP Warning: file_get_contents(/dev/fd/63): failed ...
3
votes
2answers
64 views
Setuid bit seems to have no effect on bash
I was experimenting with the security of my system and noticed something strange: setting the setuid bit on a copy of bash located at /usr/bin/bash-test seemed to have no effect. When I ran an ...
0
votes
1answer
52 views
Can I redirect output to a log file and background a process at the same time?
Can I redirect output to a log file and background a process at the same time?
In other words, can I do something like this?
nohup java -jar myProgram.jar 2>$1 > output.log &
Or, is that ...
4
votes
6answers
91 views
Getting two fields from same line together
I've got a situation where I've got several lines, and I need two different fields out of each of them. To be specific, I have a list of references in a bibliography and I want to get the last name ...
1
vote
1answer
79 views
what's wrong with embedding php scripts inside bash ones?
I was trying to use php inside bash script, but I came across several problems. My first try failed with error about bash not being able to find end of here-document. The minimal version that still ...
5
votes
4answers
153 views
Hybrid code in shell scripts. Sharing variables
This answer discusses how to run a multi-line Python snippet from the command line in a terminal. I noticed that the answer works great within shell scripts, even with nested indentation, which is ...
4
votes
2answers
99 views
Wrap command in the prompt
Is it possible to insert a separator after the command in a prompt? This is an example:
~/Desktop: ls -al
-------------------------------------
total 80
drwx------+ 6 eddie staff 204B Apr 29 ...
0
votes
1answer
25 views
Watch goes blank on refresh [duplicate]
I'm running the following command in watch. Works for the first one but subsequent ones go blank
watch diff <(pacman -Q) <(ssh kate "pacman -Q")
2
votes
1answer
83 views
bash script - supervisor program
I have to write a shell-script that have to do the following tasks:
-in every 5 seconds it saves:
-how many users are using joe and/or vi;
-if ...
3
votes
1answer
48 views
Custom key bindings for vi shell mode, ie, “set -o vi”?
I just discovered the wonders of set -o vi, and am curious if it is possible to customize this vi shell mode in some of the same ways you can customized vi or vim?
For example, create a custom key ...
0
votes
2answers
84 views
bash - reading user variable into bash script grep
I've tried every possible combination to get this bash script working. It's part of a larger script, and it basically prompts for a username (to check if it exists) and returns the appropriate ...
5
votes
2answers
98 views
Bash : command line with optional arguments
I'm running this kind of code:
#!/usr/bin/env bash
set -u
exclude1='--exclude=/path/*'
exclude2='--exclude=/path with spaces/*'
exclude3='' # any 'exclude' can be empty
tar -czf backup.tgz ...
2
votes
3answers
68 views
Colorize Bash Console Color
I need to be able to set my CentOS 6.4 bash prompt color to yellow.
I've managed to find where to set this (.bashrc) and the ANSI color for yellow (\e[0;33m).
I've setup my prompt as follows:
...
16
votes
5answers
936 views
In what situations would a user not let the shell record his command into history?
If I add export HISTCONTROL=ignorespace in .bashrc, bash won't record any commands which have whitespace before them into history. But I do not understand under what situations it will be useful. ...
2
votes
2answers
55 views
Script for opening emacs in two different ways
I've attempted to write a small script that will by default open emacs with
emacs -nw foo
by simply typing
emacs foo
and when I want a window typing
emacs foo &
The script I attempted to ...
0
votes
1answer
37 views
can someone fix my PS1 for bash
I seem to have too many colour escapes so it only works in some prompts - can someone please correct for me ?
PS1='\[\e[0:35m[\u@\e[0:33m\h\e[m \e[0:35m\w]\e[m \e[0:33m`git branch 2> /dev/null | ...
2
votes
3answers
82 views
Very strange behavior with grep and IFS
I'm having trouble using grep, the returned results are "n-empty", I mean without the 'n' character...
This is the script sample :
OLDIFS=$IFS
IFS="\\n"
i=$(grep -ril $1 *)
echo $i
IFS=$OLDIFS
...
12
votes
4answers
522 views
difference between function foo() {} and foo() {}
I can define bash functions using or omitting the function keyword. Is there any difference?
#!/bin/bash
function foo() {
echo "foo"
}
bar() {
echo "bar"
}
foo
bar
Both calls to functions ...
6
votes
2answers
96 views
Expand subshell before executing it?
I often run commands using subshells, and sometimes would like to have the subshells expanded before I run something.. This way I could verify what I'm doing, and possibly edit what's about to happen ...
2
votes
3answers
98 views
How to turn off the beep only in bash tab-complete
I find the beep useful for some things, so I only want to turn it off for tab completion (I'm not asking how to completely turn it off, that has already been answered in a different question on ...
1
vote
3answers
77 views
string and number comparsion in bash in test statements?
I am not sure about this comparison i am doing:
if [ "$exit_status" -eq 0 ];then
#some statements
fi
is this correct way of comparing numbers or quotes make the variable exit_status a ...
2
votes
1answer
36 views
replacement inside parallel command string
I want to download multiple files and save them to the md5 sum of its name:
cat list | parallel -j4 "md5=$(wget -O - {} | tee tmpfile_{#} | md5sum | cut -d ' ' -f 1); mv tmpfile_{#} $md5"
but the ...
0
votes
1answer
89 views
Multiple option arguments using getopts in bash
I am trying to process command line arguments using getopts in bash. One of the requirements is for the processing of an arbitrary number of option arguments (without the use of quotes).
1st example ...
12
votes
2answers
272 views
How to cycle through reverse-i-search in BASH?
In the terminal, I can type CRTL+R to search for a matching command previously typed in BASH. E.g., if I type CTRL+R then grep is lists my last grep command, and I can hit enter to use it. This only ...
2
votes
2answers
58 views
List all my variables [duplicate]
I'm just learning the basics, including how to declare and mess around with variables. Is there a simple way to display a list of all the variables I've named? (Everything I've found by searching only ...
4
votes
3answers
70 views
CD into directory from HISTORY in a bash script or alias e.g. $(!!)
I often want to change into the directory of a file on my file system, but I'm not sure where the file is.
I search for it like so:
find -type f -name "myfile.txt"
Lets say for the sake of ...
4
votes
2answers
75 views
What does which's --tty-only option do?
I just realized that my sysadmin has created a global alias for which:
alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
The which manpage just says:
Stop ...
1
vote
4answers
84 views
Problem understanding 'hash' command in a .sh file
So I wanted to install etherpad lite on a linux machine.
If I try to run it, I will get the Error "Please install node.js ( http://nodejs.org )"
the command 'which node' gives me the correct path to ...
4
votes
3answers
123 views
What process is running before I even get a prompt?
When I log in to a specific server I see the following:
Note that I get get Last login: ... information but no prompt. I hit Ctrl+C and only then do I get my prompt, thus proving that my username ...
2
votes
0answers
59 views
.bashrc alias not working [closed]
I have set up a few aliases in my .bashrc file, like the following:
alias ras='rails server'
alias res='redis-server'
alias rc='rails console'
alias be='bundle exec'
# git alias's are as follows
...
5
votes
2answers
65 views
Combining multiple process substitution
Suppose you tried something like this:
$ paste ../data/file-{A,B,C}.dat
and realize that you want to sort each file (numerically, let's suppose) before pasting. Then, using process substitution, ...
2
votes
1answer
30 views
how to record command which execute a programme suid
My question: Is there a way to record all commands who execute a suid programme?
Like what .bash_history do, but only the setuid programmes.
1
vote
3answers
75 views
In bash, how can I erase an alias without logout? [duplicate]
I had an alias in my .bashrc and I really don't want it anymore. I erased the alias, but my bash already has this alias loaded.
Can I erase this alias from this bash without logging out?
3
votes
2answers
47 views
Automated partition selection in bash script
I'm trying to write a bash script to run from Linux on a CD or flashdrive that can mount Windows and change stuff, but I don't know how to go about detecting which partition/drive is Windows.
My best ...
1
vote
0answers
113 views
Create adhoc network when disconnected from network
I am using ArchLinux and want to create an AdHoc network automatically when the connection to the home network drops (or the home network can't be connected to on startup). How can I achieve this?
I ...
2
votes
2answers
78 views
Why won't the for loop execute on directory
In the following script, the first for loop executes as expected, but not the second. I do not get any error, it seems that the script just hangs.
HOME=/root/mydir
DIR=$HOME/var
DIRWORK=$HOME/Local
...
2
votes
0answers
18 views
LXC apparmor profile limits executing scripts in /run/*
LXC is blocking a trusted container from running scripts in /run/*, how do I configure LXC to allow scripts to run here?
0
votes
2answers
54 views
Input/output file.txt in bash shell [duplicate]
I don't know how to read input array number in input.txt and write result in output.txt.
Example:
input.txt have array 7 8 9 2
write result sort in output.txt 2 7 8 9
How can I do it?
3
votes
2answers
38 views
Specify script to run with SSH upon login
I would like to know if there is a way to specify what script to run (on the remote machine) at login. I'm logging into a Debian box with key-pair authentiation (no password needed). The script ...
3
votes
1answer
81 views
A script's background process is still alive after closing the terminal
This is more of a process management/signal handling question than a Bash question. It just uses Bash to explain the issue.
I'm running a Bash script in which I run a background process.
This is the ...
2
votes
2answers
66 views
Calling bash from sh (dash) with commands read from args, and “Unterminated quoted string”/“unexpected EOF”
Just thought I'd document this: I'm trying something very simple - set env variable in bash, and print it out:
$ bash -c "a=1; echo a$a;"
a
$ bash -c "a=1; echo a\$a;"
a1
Now I'd want this same ...
2
votes
3answers
87 views
How to convert all .wav files in subdirectories to .aac using neroAacEnc?
I have a collection of music in .wav format, and would like to convert it to .aac/.mp4 using neroAacEnc.
How do I do this?
I am using Arch Linux x86_64 and Xterm.
8
votes
0answers
192 views
how to get exit status from the command before the last [duplicate]
I have solaris machine ( solaris 10 )
please Look on the following simple commands (haconf -makerw | grep -iq "Cluster already writable")
# haconf -makerw
VCS WARNING V-16-1-10364 Cluster ...
5
votes
3answers
201 views
difference between .* and * in regular Expression
I've a file named "test" that contains
linux
Unixlinux
Linuxunix
it's linux
l...x
now when i use grep '\<l.*x\>' , it matches :
linux
it's linux
l...x
but when i use grep '\<l*x\>' ...
2
votes
2answers
21 views
xinput - Ctrl+<Left> misbehaves if history-search-backward is mapped
I am using these lines in my ~/.inputrc:
"\e[5~": history-search-backward
"\e[6~": history-search-forward
With these settings when I type c on the prompt and do a PageUp, bash only shows command ...
4
votes
1answer
79 views
Execute multiple bash commands on the output of find
I want to execute some commands using the find -exec option, but I'm not sure what' wrong with this code. Currently, it's only processing the first find result, then getting stuck. I'm using bash in ...
0
votes
0answers
32 views
How to mimic bash tab completion behavior on OS X when using Linux
I'm an OS X user who's used to ssh'ing into various Linux machines. Recently, I installed Ubuntu on one of our servers and have noticed very different tab completion behavior in bash. Among other ...
1
vote
2answers
44 views
What does the -c option of sg do?
What does the -c option of sg do? At least on my machine, the man page fails to explain this option.
