Questions about bash only, as opposed to other Bourne/POSIX shells. For all Bourne/POSIX-style shells, use the /shell tag instead.

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0
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1answer
47 views

Log output from more than one script

I have a problem concerning the logging of a process: I have 3 scripts, a.py, b.py and c.sh a.py calls b.py and b.py calls c.sh The goal is to continuously log std out/err (write to file and ...
5
votes
3answers
82 views

How to undo changes in the commands-history?

In UNIX systems you can press top and bottom arrows to navigate through the previous commands. This is extremely handy. Sometimes, I go up and find a command that I want to use again, but with some ...
2
votes
2answers
33 views

universal help/man command: help builtin partial matches

I found a nice little script which iterates through a couple of manuals for a specific command. As a last resort, it will Google it and open a browser window. Source here: ...
0
votes
2answers
65 views

How to use 3rd variable in BASH for loop?

Good day. I want to parse data of particular columns from several files(aprilPlate.txt, mayPlate.txt, junePlate.txt, julyPlate.txt, augustPlate.txt) using For loop. The data of input files ...
0
votes
2answers
43 views

How to grep from command line for theses multiple strings?

I need to run a command to grep one of these strings from command line as web host disabled account to run website from browser until virus files are removed and I managed to collect few strings that ...
6
votes
2answers
71 views

How to check from bash if package exists in debian

I would like to make a installation bash script, where I would like to install mysql server. On linux mint I had followed code: apt-get -y --force-yes install mysql-server-5.6 but I installed new ...
1
vote
1answer
36 views

How to write a regex to look for strings with fixed length with at least one occurrence of a character

I've been doing some reading on regular expressions and thought I had everything covered, until recently. I've had to filter out all strings of length 5 which end with the letter t and contain at ...
1
vote
1answer
41 views

Script executes differently if run from udev

I'm having an issue with a script that seems really weird; it appears to stop executing prematurely when run from udev, but not when I run it manually from the command line. I've tried troubleshooting ...
0
votes
1answer
24 views

How to execute several lines into a .txt

I am using SSH; In a folder I have the next files: -rwxrwxr-x 1 german german 48 Apr 29 10:45 prueba.txt -rwxrwxr-x 1 german german 23 Apr 29 10:43 script1.sh -rwxrwxr-x 1 german german 23 Apr ...
0
votes
1answer
41 views

Script for update

I need your help in a script used for update : OLD="int 10" NEW="int 20" i=0 DPATH="/home" for f in $DPATH do sed -i "s/$OLD/$NEW/g" $f let i++ echo "modified:" $f done what i need ...
3
votes
2answers
159 views

kill: SIGSTOP: invalid signal specification error in bash script

When I use kill on command line it works. kill -SIGSTOP 1234 But if I use in bash script file I get this error: kill: SIGSTOP: invalid signal specification sh file is #!/bin/sh kill -SIGSTOP ...
1
vote
2answers
40 views

Dynamically create array in bash with variables as array name

This has been asked several times, but none of the methods work. I would like to dynamically create arrays with array names taken from the variables. So lets start with just one array for now: ...
0
votes
1answer
18 views

How to search for just new data and upload to mysql table,

I'm having a blonde moment. Problem Statement: So I have some timestamped data in a file which constantly at arbitrary intervals gets updated, and I just want to filter out data for the previous full ...
1
vote
2answers
36 views

How can I properly use the 'sed' s command in this particular scenario

There's a very simple question that's been bugging me about the sed command. Reading the documentation about this command has left me confused (mostly because English isn't my primary language). So, ...
2
votes
1answer
47 views

Execute commands from history that match regex or grep

I was wondering if its possible to execute commands from history that match a certain regex? I know you can do something like fc 232 248 And it will go into your history and then do revisions ...
0
votes
1answer
57 views

AWK is throwing an error “unexpected newline or end of string”

My Bash script: declare -a lang=('english' 'spainsh') sms="Free msg: Due to upgrades on apps you’ll need a new version by yyyy/mm/dd to app running. Visit a store or go to" url="google.com/UA2392 ...
0
votes
2answers
58 views

How to extract unknown arguments within a shell script?

I have a shell script that accepts a variety of options, some with arguments, some without, some short, some long. It should handle some of these options itself and pass on the rest it does not know ...
1
vote
1answer
47 views

How can I prepending a character for every output of a command?

I'm running commands which I want to specifically group them by every command, as shown in the example below. Tried printing with echo -e '| $line' but it only affects commands that output the text ...
3
votes
1answer
153 views

prevent a command from sending both stdout & stderr to any terminal or file [duplicate]

I would like to prevent my program from sending stdout and stderr to any terminals, files or devices. For this, I have three command crossing my mind, but I cannot distinguish their differences. Could ...
0
votes
0answers
38 views

How do I write a script for testing username/password? [duplicate]

I have about 500+ hosts I need to test a username/password combo to make sure there aren't any false positives in the list. I just need to make sure I can login and log out, no need to run anything ...
0
votes
6answers
79 views

How can I filter out a specific part of a JSON response in bash

I'm using wget with -qO to a specific updater URL for OpenELEC which provides the following JSON response, similar to the one below. ...
8
votes
1answer
230 views

Bash wildcard to match exactly n characters

Is there a wildcard in bash to match exactly 5 characters, shortening a pattern like ?????
0
votes
1answer
28 views

Dialog radiolist using dynamicaly defined array of choices

Following my previous question, I have write the following MWE to create a simple file selector by date filesArr=( $(ls -1rt ??????????_?) ) nfiles=${#filesArr[@]} iLastFile=$[nfiles-1] choiceArr=( ) ...
1
vote
2answers
60 views

Bash / Linux Tools for correcting xml

I am generating a set of 'xml' files from a 'csv' file. Some of the fields in csv file contain '&' and other invalid xml characters that need to be replaced with their appropriate xml counterpart ...
4
votes
1answer
172 views

bashrc lazy substitution

How does one get ~/.bashrc aliases to evaluate $() substitutions at run time, instead of at the time that ~/.bashrc is executed (when opening a terminal)? I run this command often enough that I would ...
2
votes
2answers
164 views

Extract group name from `id` and store it in a variable

$ id usera uid=830(usera) gid=799(groupa) groups=799(groupa) I need to extract the group name from the output of id and store it in a variable. In this case it's groupname=groupa
0
votes
0answers
24 views

mdoc warning: Empty input line #xx

while searching man pages using grep ( man tar | grep compress) I am getting this error: mdoc warning: Empty input line #xxx xxx can any number Is grep giving this error or something else? how can ...
3
votes
1answer
38 views

using shortcuts to move in bash command line [duplicate]

When I use Ctrl+Left_arrow or Ctrl+Right_arrow in bash, I move backward a "word" and forward a "word" respectively. I belive, this is defined in /etc/inputrc # mappings for Ctrl-left-arrow and ...
1
vote
0answers
22 views

How to get stdout of process? [duplicate]

I started a process from the command line, but the window server died. However I see the process I started is still running. Is it possible to connect a terminal to the process to see its output? ...
5
votes
3answers
285 views

How can I make a script take multiple arguments?

This is a very simple script #!/usr/local/bin/bash set -e if [ "$#" -lt 1 ] then echo "Please insert at least one argument" exit else echo -e "\c" fi if [ -h "$1" ] then echo "$1 is a ...
3
votes
2answers
313 views

How to print out only the script name?

[username@notebook ~]$ cat foo.sh #!/bin/bash echo "$0" [username@notebook ~]$ ./foo.sh ./foo.sh [username@notebook ~]$ Question: How can I output the "foo.sh"? No matter how was it executed.
4
votes
2answers
333 views

What defines “ll” in Fedora?

In Fedora, instead of typing ls -l, you can type ll. What causes this behavior? I've installed a new Debian system that does not appear to have this functionality. They're both running Bash. I can ...
0
votes
2answers
30 views

Add some text while output to file

Assume I have this command: ./clang-$j.out >> clang-result.txt and the each output for clang-$j.out is a fixed-length hash value (each program per line), however, I want to distinguish them by ...
1
vote
1answer
62 views

How to run a shell script (bash) on a chromebook?

I have a shell script and I need to run it in order to connect to a remote ubuntu linux machine having encrypted HDD, in order to enter the passphrase. There's a shell script for this, but I have a ...
9
votes
2answers
413 views

Jump out of a process when it get stuck

I have written a loop to iterate all .out c binary file and copy their outputs into a text file (the output for every binary file is just a one line hash value, one line output for one program). Here ...
1
vote
3answers
58 views

update-rc.d doesn't accept the header of a script file

I have beagleBoard and I want to start my script at boot time ( boot/reboot). So, i ran command: update-rc.d GatewayStart.sh defaults Output which says: header is rejected ...
2
votes
2answers
104 views

Where does the TERM environment variable default get set?

When I open a terminal window with the GNOME Terminal emulator in the desktop GUI the shell TERM environment variable defaults to the value xterm. If I use CTL+ALT+F1 to switch to a console TTY ...
0
votes
2answers
21 views

How to print arguments from a known element until an unknown element of an array with Bash

I am having a blonde moment. This is my data from myfile.csv 1429829254,e,SE,StckXchg,HDCU3000623,d,scan,253,47968,94,1420824420,JSSE-213,199,BS,KIT,*OUT* ...
4
votes
3answers
234 views

Is there a way of reading the last element of an array with bash?

If I have an array with 5 elements, for example: [a][b][c][d][e] Using echo ${myarray[4]} I can see what it holds. But what if I didn't know the number of elements in a given array? Is there a way ...
0
votes
0answers
41 views

tmux status bar path customization with sed

On the server I connnect to my home path is like this:/home/junk1/junk2/user. I can use the sed command pwd | sed -e 's|^/\([[:alnum:]]*\)/[[:alpha:]]*/[[:alpha:]]*|/\1|' to shorten the directory path ...
1
vote
2answers
58 views

Change color of input text, not output [duplicate]

I need to capture screenshots of the terminal where the typed commands visually "stand out" from the rest. Right now I'm using this to make my typed commands "red": PS1='\[\e[0;31m\]\u\[\e[m\] ...
3
votes
2answers
279 views

Why I should avoid loops in shells? [duplicate]

The following link recommends against using loops in shells. bash variables in for loop range Why is this? Here is an example loop I just happened to be looking at when I came across that answer: ...
1
vote
0answers
16 views

Is there a way to make bash recognize aliases with prefixes [duplicate]

Assume you defined the alias alias grep='grep --color=auto' in ~/.bashrc. Then invoking sudo grep wouldn't trigger the alias to be used. Is there a way to do so? If yes, would that solution be ...
1
vote
2answers
62 views

shell script to get collect pixel size of image

I'm trying to create shell script that returns the largest picture in total dimensions pixel size? For example: I have many directory over 7000+, each directory have images: dir_1/ picture_1.png = ...
3
votes
2answers
222 views

Why do I receive a “/bin/bash cannot find command” error for an alias?

I am using multiple python, I alias python3 to py: alias py="/opt/python3.4/bin/python3" I want to run python in vim so I write this: map <F9> :call SpecialCompileRun()<CR> func! ...
0
votes
1answer
36 views

Multiple input files and output files in awk

I have a folder full of text files named 000.txt to 181.txt. How can I process all of them with the same awk script (program.awk) and send them to their respective output files (output000.txt - ...
0
votes
1answer
30 views

Persistent Bash history between detached processes

I haven't yet been able to find this among the Bash documentation so I was hoping it could get answered if I asked it here. Is there any way that I can, on execution of a script, branch its history ...
5
votes
3answers
252 views

Is it possible to echo into a file, but use indenting in the shell script source? [duplicate]

If I have some nested and indented statements that echo a multi-line string into a file, the indents from the original shell (in my case bash) will be carried over into the target file. To avoid ...
1
vote
1answer
49 views

Extracting duplicity backup data

I've made some backups of my previous systems using Deja Dup (duplicity). In my current distribution it's not available, so I've simply extracted the data. Now in order to make that data meaningful ...
3
votes
2answers
43 views

Remove data from the STDIN stream buffer of another TTY session

I encountered a problem the other day while running multiple tty sessions in separate terminal windows. I was running a expensive disk access command and was waiting for it to return. Meanwhile I was ...