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

learn more… | top users | synonyms

2
votes
4answers
8k views

How to escape special characters in a string?

Assuming $file holding a value of a file name, say Dr' A.tif. In bash programming, how could I escape single quote and any other special character of the $file without removing the special character? ...
45
votes
1answer
1k views

Security implications of forgetting to quote a variable in bash/POSIX shells

If you've been following unix.stackexchange.com for a while, you should hopefully know by now that leaving a variable unquoted in list context (as in echo $var) in Bourne/POSIX shells (zsh being the ...
0
votes
0answers
4 views

Persistence 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 ...
1
vote
1answer
55 views

How to tell “grep -w” what characters make up “words”?

$ printf 'asf .test. afd\nasaf foo-test asfdads\n' asf .test. afd asaf foo-test asfdads $ printf 'asf .test. afd\nasaf foo-test asfdads\n' | grep -w test asf .test. afd asaf foo-test asfdads ...
5
votes
3answers
311 views

Compare the heads of two files in bash

I can do diff filea fileb to see the difference between files. I can also do head -1 filea to see the first line of filea or fileb. How can I combine these commands to show the difference between the ...
1
vote
3answers
44 views

Last exit status from within script without source

Supposing someone invokes a non-existent command, the only way I know to retrieve its error status from a script I execute right after is by using source I.e., let's say this script's name is dummy ...
4
votes
3answers
207 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 ...
0
votes
1answer
32 views

command “find … -exec mv …” created a file with strange content

I wanted to move binary files from folder /myhome/sourcedir to /myhome/targetdir. I used a command find /myhome/sourcedir -type f -cmin +3 -exec mv '{}' /myhome/targetdir ';' Folder /myhome/sourcedir ...
1
vote
1answer
16 views

Git alias multi-commands with ; and &&

I want to have an alias that execute a command and then whether it fails or no it execute other commands that depends on the success of each other. So I have something like that in .gitconfig ...
1
vote
2answers
31 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 ...
0
votes
0answers
14 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 ...
0
votes
0answers
40 views

Shell intervals using awk

I have a file a 10:10 10:30 b 12:15 13:15 c 16:54 17:54 and I need to enter interval for example 10:15 so my output should be a 10:10 10:30 How I need to do that using awk?
-1
votes
0answers
28 views

Shell script for electrum - how to add the seed? [on hold]

I use a diskless web server with a live cd and looking for a possibility to restore my electrum wallets automatically by a seed. I would like to implement a script that performs this task for me. so ...
1
vote
3answers
3k views

Comparing two files in a script

#!/bin/bash while read file1 <&3; do while read file2 ; do if [ $file1 == $file2 ] ; then $file1 >> /infanass/dev/admin/test/newlist.txt fi echo ...
0
votes
1answer
23 views

Run script from GUI with terminal output

I would like to run a script from the GUI. For example a simple echo "hello" from the right click context menu. In my case I would set up an action in thunar like this: Then it appears in the ...
1
vote
2answers
26 views

Using sed to replace javascript code in multiple files

I need to replace an old google analytics code with the new universal tracking code in lots of static html files. The old code looks like this: _uacct = "UA-XXXXXX-X"; urchinTracker(); The new code ...
18
votes
4answers
40k views

Shell script fails: Syntax error: “(” unexpected

I've been working on a script that automates setting up a development environment for Raspberry Pi development (step by step details that work are here). The script is linked in that article but ...
2
votes
1answer
31 views

Expand variable in brace expansion [duplicate]

I am trying to enumerate a range of integers using a variable but having some trouble. When I type echo {1..5} I get 1 2 3 4 5 However, when I type a variable, I am unable to get the ...
2
votes
1answer
25 views

How to download a lot of documents on the terminal from a server?

I have to write a bash script (.sh) with less than 300 characters which downloads all of the genomes 22 in this server ftp://ftp.ncbi.nih.gov/genomes/Homo_sapiens/ (the ones with fa.gz extention) and ...
1
vote
1answer
26 views

Get first/second file column

I have two for loops here for i in $(cat "firstFile.txt") do for j in $(cat "secondFile.txt") do if [ "$i" = "$j" ]; then echo $i[$2] # use first file second column ...
4
votes
3answers
214 views

why bash increment: `n=0;((n++));` return error? [duplicate]

n=0; ((n++));echo "ret=$?;n=$n;" ((n++));echo "ret=$?;n=$n;" ((n++));echo "ret=$?;n=$n;" from n=1 on, ((n++)) works correctly, only when n=0, ((n++)) return error, and I am using a trap '' ERR that ...
4
votes
1answer
100 views

Redirection to file does not work properly

I have here a bash script: #!/bin/bash TARGET_FILE=ping_result.txt # declare the target ip addresses declare -a ips=("XXX.XXX.XXX.XXX" "YYY.YYY.YYY.YYY") function print_and_log() { echo "$1" ...
0
votes
0answers
27 views

Using nice on bash (or other) subshell?

Say I'm working on a sluggish system and notice (say via top) that CPU usage is up around 100%, but I don't want to kill the process. If I want to do other work on the machine and just make that ...
0
votes
0answers
18 views

output in columns [duplicate]

i am trying to put my data after a snmp walk in a table this is my code: for i in `cat $Rep_Scripts/IP_ALU_LIST.txt | awk '{print}'` do read hostname ip <<< $(echo $i |sed 's/;/ /') ...
4
votes
3answers
5k views

Pipe assigns variable

For simplicity I would like to do: echo cart | assign spo; echo $spo Output: cart Does such an assign application exist? I am aware of all the ways to do this using substitution.
2
votes
2answers
358 views
+50

Gnome 3.10 ScreenCast + Audio on Arch

I'm trying to record my desktop (including audio) in Gnome 3.10 on Arch Linux with the built-in screen recorder (Ctrl+Alt+Shift+R). According to this post (and other similar solutions that can be ...
7
votes
6answers
6k views

How do I suppress dd output?

I have a bash script that creates some file using dd. The problem is dd throws a great amount of output that is going to mess with the output of my script. Searching around I've found a solution: dd ...
0
votes
0answers
44 views

Schedule backup with notification?

To avoid editing files at the same time of backup scheduled by cron, I figure out a way: Before backup, send a desktop notification such as notify-send -t 0 "Ready for backup", to let me prepare ...
0
votes
0answers
22 views

RHEL Bash Script for Oracle WebLogic - Run command as another user; No such file or directory

I'm trying to run a test script which switches to a WebLogic 10.3.6 user and checks the status of the admin server. The script works fine when the variables are replaced with absolute paths, but this ...
1
vote
1answer
26 views

Bash completion - How to get filename completion for suboptions

I have a function which can take main arguments and then sub-arguments. Some of these sub-arguments are filenames. The current completion code I have is as follows. _scm() { local cur prev opts ...
1
vote
3answers
45 views

bash: Saving aliases beyond one session

Recently, I've been fiddling around with Linux's terminal commands to try and get a better feel for the system. I was happy to know that I could give commands a different name in order to call them, ...
1
vote
1answer
35 views

How to wrap bash commands after adding color

My current .bash_profile is equal to the below. I add some color and add a command that outputs whether or not I am in a git repository to my PS1 for my bash profile. ORIG=$PS1 ...
1
vote
1answer
64 views

bash scripting : using expect

I am facing an issue when I run simply these commands. The remote server want to pass "yes" to add the key in RSA file because first time connection established with scp. commands are given below ...
4
votes
4answers
925 views

Using GNU Parallel With Split

I'm loading a pretty gigantic file to a postgresql database. To do this I first use split in the file to get smaller files (30Gb each) and then I load each smaller file to the database using GNU ...
-2
votes
2answers
51 views

Change file name in different path [duplicate]

I would like to know how to rename the same log file which is in different path. I mean, the log file is in /main/rel/1.2, /main/rel/1.3, /main/rel/1.4, /main/rel/1.5 etc. I want just do it from ...
0
votes
1answer
22 views

need help with inserting variables in a file path on GNU linux (SLES 11)

I am tryin to insert 3 variables to build a path, but unable to get it . I am trying the below log_path="/vol02/logs/$dname/logs/103602_$msname/${msname}_start.log" dname=cfp msname=cfp003 i get ...
1
vote
3answers
3k views

Using awk to process ls output with spaces in filenames/paths

All, I have a script in which I use find command to filter out all png files in a given folder and list them along with their size. I want the output in the following format: someFile.png => 1.2K ...
1
vote
2answers
62 views

How to strip time stamps from a file?

I have log which contains lines of data: Mon Apr 20 03:15:18 EDT 2015: my|data|data|data I am trying to write a script which would extract just the data from the log, stripping the leading time ...
1
vote
1answer
25 views

How use '(' token when using it for searching with ag / awk?

$ ag findVersions( src/java/com/google -bash: syntax error near unexpected token `(' I tried quoting it, escaping it, both were not suitable. $ ag findVersions\( src/java/com/google ERR: ...
1
vote
1answer
42 views

Getting Python errors whenever I try to use terminal in Linux Mint

I've had Mint installed as a dual boot on my laptop for some time. I use it as my dev environment, for desktop and web related coding. I recently started getting errors which have rendered my terminal ...
3
votes
2answers
82 views

bash - wrong key sequence bindings with control+alt+space

I am trying to install some key sequence bindings but I have trouble. My shell is bash, my terminal is gnome-terminal, and my system is Ubuntu 14.04 in graphic mode. Edit : my keyboard is french ...
1
vote
1answer
47 views

Redirect the output of a query in a file

How I can do to redirect the query result in a text file in sqlplus I tried: start requete.sql > resultat.txt but it dosen't work
4
votes
3answers
78 views

Adding vertical space after command in bash

How to add vertical space after each command in bash? Looking for a wee bit of vertical space, not a full line. 1/4 or 1/3 of the line height should do it. [edit] The space to add is only after the ...
2
votes
2answers
52 views

Joining bash arguments into single string with spaces

I'm trying to join all of the arguments to a Bash function into one single string with spaces separating each argument. I also need to have the string include single quotes around the whole string. ...
1
vote
2answers
645 views

refresh bash tab completion

I have a script for auto-completing my ssh-hosts. If I change my ~/.ssh/config the auto-completion is not updated automatically, though. This does not surprise me. In a new shell, the new entry is ...
0
votes
2answers
25 views

Exclude the output from ssh and only log the error if found

typeset -f | sshpass -e ssh -o StrictHostKeyChecking=no user@${IPADDRESS} " $(cat); IFERROR=$(checkscript); echo "$IFERROR"" > ${SSHTEMPFILE} 2>&1 This line...I can't exclude the ...
-3
votes
0answers
15 views

bypass Kali GNU/Linux 2.0~alpha1 kali tty1 [on hold]

how to bypass Kali GNU/Linux 2.0~alpha1 kali tty1, it happens after I updated my kali running the commands apt-get install update apt-get install dist-upgrade reboot
3
votes
1answer
180 views

Linux: set command for local variables

I am trying to understand local/environment variables and export/set commands. $ set FILEM="razrax" $ echo $FILEM $ FILEN="test" $ echo $FILEN test Please explain why echo $FILEM returns empty ...
73
votes
19answers
59k views

How can I get my external IP address in bash?

I need to find my external IP address from a bash script. At the moment I use this function: myip () { lwp-request -o text checkip.dyndns.org | awk '{ print $NF }' } But it depends on ...
0
votes
0answers
20 views

Sed replace with command output [duplicate]

I'm trying to replace text with the contents of a file and I'm getting errors. This works: cat /tmp/test | sed -e "s/__TEST__/$(cat pass)/g" But this one doesn't cat /tmp/test | sed -e ...