The shell is unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks. Use this tag for questions applying to /bin/sh and most compatible shells (ash, bash, ksh, zsh, …).

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2
votes
3answers
27 views

get the apache document root using shell script

I am creating an RPM and in the pre stage, I want to determine apache's document root so I can copy the web application files there. First, I check if apache is installed. If apache is installed, ...
4
votes
4answers
1k views

Why does `rm -f !(/var/www/wp)` leave files behind in /var/www?

Why does the rm -f !(/var/www/wp) command have no effect? I want to remove all the files in /var/www, except for the /var/www/wp directory, which should remain. root@born:~# ls /var/www ...
0
votes
3answers
40 views

Replacing line with its line number

How can I replace the whole line with no matching pattern just with the number of the line? sed -i "${line}p c\ "$PWD" " file.txt
0
votes
1answer
20 views

Rename and copy/move sets of similar named directories to another location

For a set of directories with similar names at different location, /foldX/dirA with sub-directories aa1 aa2 aa3 aa4 aa5 /foldZ/dirA with sub-directories aa1 aa2 aa3 /foldY/dirA with ...
-1
votes
0answers
41 views

What exactly is Ctrl + s? [duplicate]

In my terminal, if I press Ctrl+S it 'freezes' output, which can then be resumed with Ctrl+Q. What exactly happens here? What library/program supplies this functionality or at least says what ...
2
votes
4answers
109 views

How do I perform xargs grep on grep output that has spaces?

I'm searching for files based on a regular expression, and then I'm trying to search those files for content. So, for example, I have something like #Find all C++ files that match a certain pattern ...
26
votes
4answers
2k views

Why do many commands provide a “quiet” option?

Why do many commands provide the option -q or --quiet to suppress output when you can easily achieve the same thing by redirecting standard output to the null file?
1
vote
1answer
34 views

mv to file with

I ran the following mv command, apparently by mistake using backslashes by mistake instead of slashes. mv 2015-02-02_flyer_ppces.pdf ..\PPCES2015\2015-02-02_flyer_ppces.pdf The output is empty. ...
4
votes
2answers
198 views

BASH base conversion from decimal to hex

In Bash, how does one do base conversion from decimal to another base, especially hex. It seems easy to go the other way: $ echo $((16#55)) 85 With a web-search, I found a script that does the ...
1
vote
0answers
14 views

How to move directories based on the output of rhash (CRC32 check of .sfv) with bash/perl?

My idea, is to move the CRC-check OK folders (albums) into a lets say "complete+CRC_OK" folder with a script once per day in cron. I would need to put the rhash command in a loop with number of ...
5
votes
2answers
191 views

How to count duplicated last columns without removing them?

I have a file that contains 4 columns. I want to compare the last three columns and count how many times they occur without deleting any of the lines. I just want the count to be present in front of ...
12
votes
6answers
395 views

Extraction of .gz files contained in a folder

I have a folder containing approximately 320116 .pdb.gz files. I want to uncompress them all. If I use gunzip *.gz it gives me an error i.e. argument list too long. The folder is about 2GB. Please ...
0
votes
2answers
36 views

how to split the string after and before the space in shell script?

I am having a variable which shows on echo like this $ echo $var 129 148 I have to take only 129 as output. How will I split 129 and 148?
-1
votes
0answers
34 views

How can I encrypt specific words in a text file with a bash script? [closed]

I want to encrypt same words in a text file and I want to know how I can do it in bash. For example, if the file contains: The employee Kim Van, his registration number is ID721 he is work in the ...
0
votes
0answers
30 views

calling funtion of shell script file from java with an argument [closed]

I am trying to call a shell script file with one argument. But it is not working. What is the way to call this? And can we call a function of shell script file directly? From the servlet class I want ...
2
votes
2answers
131 views

An error of variable type?

I've an error that I don't understand, it seems that that the problem is that my parameters into the shell are not of the same type as what they are in my SQL Database. For a better understanding: ...
0
votes
1answer
40 views

introduce a c script in a bash file [closed]

My problem is to recover data keyed in text file in bash. I seek the command that can perform this task and I used sed, awk and even cut but I have not succeeded. One friend of mine suggested to ...
8
votes
2answers
205 views

How bash treats “> >()”

While experimenting with output redirection and process substitution I stumbled upon the following command and its resulting output: me@elem:~$ echo foo > >(cat); echo bar bar me@elem:~$ ...
0
votes
1answer
19 views

Why doesn't commons-daemon ./configure recognize $JAVA_HOME? [closed]

I'm trying to install a tomcat 7 server. I'm following these instructions from the tomcat 7 docs. I also set my JAVA_HOME variable in ~/bashrc as well as ~/.bash_profile and /etc/profile. I can do ...
1
vote
1answer
40 views

What is an alias really doing?

I'm looking for a way to check what an alias is really doing, without having to check the ${HOME}/.profile file, or whatever other file where you can define an alias. For example, if I run ll and I ...
2
votes
1answer
14 views

Making XMODIFIERS=@im=none emacs24 standard

I run emacs as XMODIFIERS=@im=none emacs24, otherwise some multi-keys for typing things like à won't work. How can I make this option permanent, so when I type emacs24, it runs as XMODIFIERS=@im=none ...
4
votes
4answers
131 views

Insert new lines with missing values (NA)

I would like to insert new lines in text files if there are missing values. I have for example the following text file (A.txt), for which line 5 is missing. In addition, as the file should have 12 ...
2
votes
1answer
121 views

Transform .csv into 3 columns and a row

Sample Input: id,Product1,Product2,Product3,Product4 1,0.1,0.3,0.8,0.7 2,0.6,0.7,0.5,0.9 I need output as : id,productname,product_val 1,Product1,0.1 1,Product2,0.3 1,Product3,0.8 1,Product4,0.7 ...
-4
votes
1answer
50 views

shell script for two numbers [closed]

Write a shell script to take two numbers from command line and show result of dividing small number with bigger number. Also note that it should not accept zero or negative number. If user enter ...
1
vote
0answers
46 views

How to move /usr folder and replace it with saved copy [duplicate]

If I made a backup of /usr with: # cp -r /usr /usrRESERVE1 how can i switch it back after some time: 1# mv usr usrRESERVE2 2# mv usrRESERVE1 usr second command will not work because mv is inside ...
1
vote
1answer
42 views

Ctrl+C process termination without Terminal killing

I started using Sublime Text 3 to compile my FreeFem scripts (interpretator PDEs package solver) under Ubuntu 14.04. To invoke the interpretator I customized the build system as follows "shell_cmd": ...
3
votes
2answers
68 views

save the number of files only in a specific folder

I'm using this script to save the number of files in a main folder, but it also counts the subfolders inside that main folder. nfiles=$(ls -1 /home/userA/mainfolder | wc -l) Any advice how I can ...
-2
votes
1answer
36 views

Append the content of a file to the value of a variable in ksh

Can we append the content of a file to the value of a variable in the Korn shell? How? /bin/ksh: $ B.11.31 Oct 1 2008 01:54:10 $ Version 11/16/88 blok.c $Date: 2008/08/20 12:15:51 $Revision: ...
0
votes
0answers
21 views

Linux . Kali on android 4.2.2

hope this topic finds you well E: Unable to Locate Package thats the error that occur when i try to install any tool in kali on android I'm using Android with version 4.2.2 and kali is working well ...
3
votes
2answers
132 views

How do you stop a bash shell expansion?

I know some methods for stopping process. When I type: echo {1..999999} > filename.txt I can't stop it from running. I can stop other processes with Ctrl+C | Ctrl+D | Ctrl+\ and etc. But none ...
1
vote
2answers
33 views

Need special validation for shell script

I want to create a bash script which will have lot of options while executing. # script.sh --dry-run --user <parameter1> --pass <parameter2> I heard about getopt option but looks like ...
0
votes
2answers
27 views

Why is wget still failing even after enclosing the URL with double quotes?

I enclose URLs I want to wget with "" since most of them have spaces, braces, etc. It usually works fine, but I can't get this URL to work: wget "http://xxxx/Sankarea - 6 - It`s Because I... Ran ...
1
vote
2answers
47 views

sh -c: Unterminated quoted string error [duplicate]

I've spent hours trying to understand the following error. My Script CMD="sh -c 'echo \"a\"'" $CMD Error: "a"': 1: "a"': Syntax error: Unterminated quoted string of course when I do echo $CMD ...
1
vote
2answers
274 views

How to put $@ in quotes?

My bash script looks like this: #!/bin/bash grep -r --color=always $@ . | nolong The file is saved in /usr/bin/findstr Everything's ok when I run this: findstr hello But when I run this: ...
1
vote
1answer
35 views

Saving colored output regardless of the source

How can I save colored output to a file regardless of the source when the sources turn coloring off if they detect their stdout isn't a terminal?
-1
votes
1answer
22 views

Remove line breaks in a FASTA file

I have a fasta file where the sequences are broken up with newlines. I'd like to remove the newlines. Here's an example of my file: >accession1 ATGGCCCATG GGATCCTAGC >accession2 GATATCCATG ...
2
votes
2answers
154 views

How does one append a unix timestamp on a filename which is inside an argument?

To be more specific, I want the Unix timestamp to be appended to my file name: db:backup --database=mysql --destination=s3 --destinationPath=date+random.sql --compression=gzip However, this gives ...
-1
votes
2answers
54 views

Difference between 'echo' and 'echo -e' [closed]

What is the difference between echo and echo -e? Which quotes should be used to execute a command after echo ie: echo "..." or echo '...'? Also what functions are available for the command echo?
-2
votes
1answer
46 views

How to parse json output through shell / Python [closed]

I am running a curl command which gives me json response. Now I want to parse the response output to get the keys and corresponding values from the output or getting value for a particular key. I ...
0
votes
0answers
32 views

How can I disable FTP access/login for users

I want to temporarily disable the FTP Access of the FTP users I have tried following commands for user "aadmi" but still able to login sudo passwd -l aadmi which said Locking password for user ...
3
votes
3answers
118 views

Understanding Bash's Command Substitution

I am trying to understand how exactly Bash treats the following line: $(< $FILE) According to the Bash man page, this is equivalent to: $(cat $FILE) and I can follow the line of reasoning for ...
1
vote
1answer
35 views

Not getting the desired output for echo command [duplicate]

Below is my script. #!/bin/bash SERVERS="sl20rht00-t" #SERVERS="shcbrht01-t" USR="adm-dt-c" for host in $SERVERS do ssh -tt $USR@$host 'sudo cp /etc/sudoers /Backups/sudoers_11thmarch2015; sudo cp ...
1
vote
1answer
87 views

permission issues while doing ssh setup in cygwin

I'm trying to setup ssh-host in cygwin. Getting the below error: *** Warning: The permissions on the directory /var are not correct. *** Warning: They must match the regexp d..x..x..[xt] *** ERROR: ...
3
votes
2answers
136 views

Meaning of `cat /dev/null > file`

In a document created by a former coworker there is this command: cat /dev/null > /var/spool/mail/root It says next to it that it will clean out mailbox. Can someone please explain how/why ...
-2
votes
2answers
31 views

grep to get all the getters from a java file

I have a java file called Friends.java . There are 5 variables and each variable has its own getter. Assume that all the functions below follow standard java standard, i.e public methodName(){ //Some ...
5
votes
4answers
373 views

list graphical processes from terminal

Do no confuse the question here with how to list processes graphically, that is not what I am asking. In the Terminal, how can i see which processes have a GUI? as in things like firefox, vlc, ...
1
vote
1answer
56 views

Shell : while read line nested

I've two documents: doc1.lst and doc 2.lst I want to take the content of each line and put it as parameters for my SQL query. I tried something like this, please correct me file=doc1.lst ...
0
votes
2answers
59 views

ssh inside a script with 'command' instead of “command”

I am trying to run commands on various nodes of our cluster automatically via a simples script. I have seen that I can run: #!/bin/bash echo "Machine: "$HOSTNAME; ssh machine2 'echo Machine: ...
0
votes
1answer
16 views

User session connected

When i connect to ssh directly via terminal on unix machine how can i know how many session has been escalated ? i mean Fisrt i connect as root # and su bryan # and su tony # and su emilie # ...
0
votes
1answer
91 views

Linux Bash Script Ideas [closed]

I have been given the task of creating a shell script to show my proficiency in scripting. I am really struggling with ideas on what to do. I would like to create something that is relevant and could ...