Bash is the shell from the GNU project. It is the standard shell on many Linux distributions and often available on other *NIXes.
0
votes
1answer
75 views
Guide/help using Dialog with bash scripting
While I understand how to create menus, no guide I've found teaches how to actually link them to commands
I was hoping to have something like:
dialog--clear --title "n00b's spellbook" \
...
4
votes
3answers
76 views
Why should 'Character Classes' be preferred over 'Character Ranges' In Shell (Bash)?
The Linux Command Line (Book - page count 47) says:
... you have to be very careful with them [character ranges] because they will not produce the expected results unless properly configured. For ...
3
votes
1answer
84 views
bash: different output between CTRL-C vs “ordered cleanup”
I really tried to find a better title for this question. I am open for suggestions.
I've written a bash script that traps EXIT and calls a function if that signal is received. It calls the same ...
0
votes
2answers
71 views
Supress expansion of * in echo
I am working on a script which dynamically executes some queries on daily basis. These queries are coming from a table in the database.
Here is the sample output of the query table:
...
2
votes
5answers
96 views
Command substitution - single quotes and spaces
How can I make command substitution pass a list of single-quoted POSIX paths separated by spaces?
command1 $(command2)
command1 '/path/to/file 1' '/path/to/file 2' '/path/to/file 3'
How can I trace ...
1
vote
3answers
386 views
How to test if a variable is defined at all in Bash prior to version 4.2 with the nounset shell option?
For Bash versions prior to "GNU bash, Version 4.2" are there any equivalent alternatives for the -v option of the test command? For example:
shopt -os nounset
test -v foobar && echo foo || ...
0
votes
1answer
56 views
svn backup bash script errors
I have created bash script for create dump of svn repositories. I want to add such functionality that after dump of every repository script send it to remote server using rsync and delete from dump ...
2
votes
2answers
117 views
IFS change not coming into effect
I was trying to change the IFS(Internal Field Separator) character to comma for a file processing, but to my surprise the IFS was un-changed.
Here's the order of commands and output :
...
3
votes
1answer
35 views
Is there an easy way to change bash suggestions?
I've noticed that some console commands (like sudo or xargs) are using different kind of suggestions when I press Tab (they suggest programs instead of files).
Is there a way to mimic that kind of ...
5
votes
2answers
103 views
Reference prior command output / terminal screen contents in current command line
I often need to copy an output line in Bash in its entirety:
$ grep -ilr mysql_connect *
httpdocs/includes/config.php
httpdocs/admin/db.php
statistics/logs/error_log
$ vim ...
1
vote
0answers
68 views
Using sshpass, return code (exit status) differs for reasons unknown using valid commands
There are a few things going on here but I think ultimately, either CLish or SSH is returning an exit code that is messing up my work flow.
I'm attempting to connect to a remote machine (CLish shell) ...
1
vote
3answers
225 views
Find files in multiple folder names
I am trying to list all the files from dir1, dir2, dir3 and dir4 which might be anywhere in as a sub directory of my cwd using the find command. I tried the following with no success:
find . -type f ...
1
vote
2answers
68 views
How to print shell variables and values to be able to copy/paste them?
In Bash 4.2.25, the set and env output is not escaped, so shell escapes and any non-printable characters won't be copy-pasteable. Take for example this shell session:
$ export foo=$'a\nbar=\baz'
$ ...
-4
votes
1answer
108 views
zsh: Is it worth the switch from bash? Is it the time? [closed]
I have been a bash user for years now. However, I find that zsh is increasingly gaining momentum. I came up with the following questions:
Is zsh really becoming that popular? Will it compete with ...
3
votes
3answers
90 views
Can't process stdout with pipe as it comes
I'm running tshark on a fifo, and the following is a bare example of a loop that prints the output of tshark as it comes:
tshark -i $fifo | while read line; do
echo $line
done
The problem ...
0
votes
2answers
51 views
How to convert multiple XCF files to PNG?
I have a folder with a lot of xcf files which I want all to be converted to png files, at best via a one-liner from bash.
How can I achieve such a task?
-2
votes
1answer
50 views
Paths in my bash profile do not work!
export PATH=/usr/local/bin:/Users/rodrigoprugue/Desktop/CRUNCH:~/phreeqc/bin:$PATH
export PARFLOW_DIR=~/parflow/parflow.r605/
export SILO_DIR=~/parflow/silo-4.7.2/
export ...
4
votes
3answers
238 views
Is there a way to call a command with a set time limit and kill it when that time passes? [duplicate]
Possible Duplicate:
Run a command for a specified time and then abort if time exceeds
I was working on a continuos integration build script when a need for such a command arose. Basically ...
4
votes
4answers
125 views
Detecting X session in a bash script (.bashrc etc.)
Recently I put xset b off to my .bashrc. Now I'm annoyed by the error thet pops up when I log in via tty or via ssh, i.e. outside X session.
First thing that came in my mind was [[ -z "$SOME_VAR" ]] ...
1
vote
1answer
64 views
Safely convert unicode strings to printable characters
I have many HTML files containing mixed unicode strings like \303\243 and printable characters like %s. What I'd like to do is converting the unicode strings into printable characters in a safe way.
...
2
votes
1answer
40 views
Opening a usable xterm window through bash script
I often have projects for which I need multiple terminal windows open at different locations, and setting up my workspace each time I want to work on this project takes a long time, so I'd like to be ...
0
votes
1answer
32 views
Why are bash_completion scripts persistently in environment?
I accidentally typed the command export into my console emulator (running Bash) instead of export -p, and now all the bash_completion scripts are persistently in my environment, even surviving reboot. ...
2
votes
2answers
30 views
How can I set a bash alias that evaluates $() when run?
I set up an alias:
alias gpgagentexport="eval $(cat ~/.gpg-agent-info) ; export GPG_AGENT_INFO"
However when I source my .bashrc the $(cat ...) is evaluated at that point. But I want to evaluate ...
2
votes
2answers
76 views
what is the difference between if and [[ in bash?
I see that
if cmd
then
echo Hi
fi
works differently from
if [[ $(cmd) ]]
then
echo Hi
fi
So what happens when there is a [[ and when there is not?
3
votes
1answer
62 views
Prompt for confirmation for every command
I'm writing a pretty ad-hoc install script for some thing. No much control constructs, basically just a list of commands. I'd like the user to confirm each command before it gets executed. Is there a ...
11
votes
6answers
6k views
How do I can get the size of a file in a bash script?
How do I can get the size of a file in a bash script?
How do I assign this to a bash variable so I can use it later?
1
vote
2answers
61 views
bash if statement behaviour question
I wrote this following piece of bash script.
if [ $(tmux has -t junk) ]
then
echo zero
else
echo one
fi
It always returns one, no matter if the session exists or not. I checked in the command line ...
1
vote
1answer
40 views
Execute commands coming from a serial port
I have some hardware that is sending commands over /dev/ttyACM0 every once in a while and I'd like to execute them in a terminal. For example, if the ascii "ls" comes over /dev/ttyACM0, I'd like to ...
9
votes
6answers
3k views
Execute a specific command in a given directory without cd'ing to it?
Is there a way to execute a command in a different directory without having to cd to it? I know that I could simply cd in and cd out, but I'm just interested in the possibilities of forgoing the extra ...
2
votes
2answers
97 views
Bash string comparison inside if [closed]
Read that for comparing string inside if we need to use double square brackets. Some books says that comparison can be done by =. But it works withe == also.
#!/bin/bash
a="hello"
b="world"
if [[ $a ...
1
vote
2answers
45 views
How do I get a field in bash's job list using awk?
I wanted to write a function to retrieve a field from the list of background jobs in bash. For example to get a specific argument.
Let's say I send vim to the background, so "jobs" displays this ...
1
vote
3answers
316 views
Evalute passed in variable in bash
Is there a way to pass in a variable as an argument to a bash script and have it evaluated scoped by the bash script?
Given:
# cat /path/to/file/of/host/names
bob
tom
joe
etc...
# dofor
FILE=$1
...
6
votes
4answers
2k views
Number of files containing a given string
How can I count the number of files (in a directory) containing a given string as input in bash/sh?
5
votes
2answers
1k views
Is there a way to detect null bytes (␀, NUL, \0) in sed?
Related to another question, in order to fuzzily detect binary files, is there a way to detect ␀ bytes in sed?
1
vote
2answers
76 views
How do I set bash aliases and variables from within vim?
In cmdline mode, the following examples do not work for me.
!alias lol='echo lol'
!lol='echo lol'
3
votes
1answer
95 views
Delete whole argument in current bash command-line
Using ^W (unix-word-rubout) I can easily delete a single "word" from the current command in my bash shell.
However, when dealing with quoted arguments that contain spaces (or unquoted arguments ...
2
votes
5answers
3k views
make grep output without trailing newline
Please consider this snippet:
X=$(grep -m1 'some-pattern' some-file | sed -n 's/.* //p')
I want to put last word in a variable if some pattern condition is matched for lines in arbitrary text file
...
0
votes
2answers
50 views
Command in a variable [duplicate]
I am trying to run a statement where the name of the command is in a variable. For example:
my_command='/path/to/some/command'
$my_command -f foo -b bar -s something else
But the above does not ...
1
vote
1answer
121 views
How to create a password protected shell script [duplicate]
How can I create a password-protected shell script for read/write access. It should also be executable by all users without the password. I have sensitive information in the script.
1
vote
1answer
76 views
What is a sure fire way to find all files and/or path that contains 2 keywords?
I was doing a
find . -iname '*sitesearch*' | grep demo
because I know the file should be some/path/SiteSearch/demo/SiteSearch.html, but it turned out a person put the file in as ...
1
vote
3answers
118 views
Why is this Bash command using regex not replacing my brackets?
I have this command to go through all my files in my Music directory, and all subdirectories, and replace any square brackets in the file name with rounded brackets:
find /home/Music/ -depth -name "* ...
3
votes
2answers
154 views
Limit stdout from a continuously running process
I haven't had much luck finding an answer to my problem, but maybe I'm not asking for it correctly.
I have a process I startup like the following:
nohup ping 127.0.0.1 > log.txt >2>&1 &
...
0
votes
1answer
42 views
Display ONLY IP addresses of currently logged users
I want to get a list of the currently logged users and their respective IP addresses.
I tried the following command line:
w -s
However, the TTY, IDLE and WHAT columns are also displayed. I don't ...
3
votes
4answers
144 views
How to remove files which do not end with “.c”?
I have a directory which contains all the C programs. I have also compiled them at the creation time so as to check my code. There are a lot of programs nearly 100 of them. So I want a BASH script ...
2
votes
2answers
60 views
Strange crontab-script interaction (bash)
I'm running Ubuntu 12.04 and bash. I've written a pair of shell scripts that allow me to set an alarm which, after ringing, unsets itself. The first, alarmset, allows me to enter a time and modifies ...
0
votes
3answers
126 views
Regular Expression for finding double characters in Bash
I am looking for a regular expression that finds all occurences of double characters in a text, a listing, etc. on the command line (Bash).
Main Question: Is there a simple way to look for sequences ...
3
votes
1answer
629 views
A tee >( process ) is truncating its stdout when writing a file
When I use tee to pipe stdout directly to a "specific block of code" (which then writes the modified data to a file), I always get the full complement of exptected output lines in the file.
...
8
votes
5answers
232 views
Can I select only one result from a bash glob?
I'm trying to write a script for work to automate some reporting on an output. The Log files are (currently, it's being 'standardise' in the future) stored in this sort of path structure:
...
3
votes
5answers
180 views
evaluate multiple patterns from program output and write into pattern specific files
I have a script outputting some value/numbers and I want to split those into two files. I am looking at something like:
./runme.sh | grep 'ook' >> ook.out | grep 'eek' >> eek.out
Where ...
6
votes
3answers
916 views
Switching to `zsh`: Are all bash scripts compatible with `zsh`?
I'm looking to switch from bash to zsh but concerned about compatibility of bash scripts.
Are all bash scripts/functions compatible with zsh? Therefore, if that is true is zsh just an enhancement to ...
