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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3
votes
3answers
76 views

How to separate numerical values from identifiers

I'm currently writing a shell script that seperate values from their identifiers (retrieved from grep). For example, if I grep a certain file I will retrieve the following information: value1 = 1 ...
1
vote
1answer
97 views

How to make ZSH tab completion work with two tabs

I saw a question like this on here, but the answer didn't work for me. I'm trying to set up tab completion and I want it that if I have two files fileA and fileB and I type fil<tab> it first ...
5
votes
3answers
5k views

Add directory to path for all shells and users in SLES 11.1

I'm using a server running Suse Enterprise 11.1. I need to add some locations to the path for all users and for all the shells. Is there a nice and easy way to do this or do I have to modify the ...
2
votes
2answers
618 views

Matching two files for similar first line

I have 2 set of files. File one contains ID's ex: 1111 2222 6666 3333 4444 File two contains ID and username: 1873 Neil 1111 Roger 7632 Tim 3333 Oscar 8723 Greg 4444 Roy 6666 Patrick I want to ...
2
votes
1answer
94 views

Message appears after every command completed

I am very new to Linux. Having said this, I had a friend go on my RHEL machine and he somehow added a few random lines in a file, which will post every time I have completed a command. I am not sure ...
1
vote
2answers
919 views

Ignore all matches to negated extglob pattern in recursive ls

I would like to recursively list all files in a directory which match a given input pattern using ls. (Oh, and this is in Bash). The only way I can think of to do this using ls is to shopt -s extglob ...
10
votes
2answers
23k views

How to cut (select) a field from text line counting from the end?

I know how to select a field from a line using the cut command. For instance, given the following data: a,b,c,d,e f,g,h,i,j k,l,m,n,o This command: cut -d, -f2 # returns the second field of the ...
1
vote
2answers
244 views

Shell : Сopy one directory to multiple directories

There is a directory YYY and a structure on the site: site1.ru/wp-content/plugins/ site2.ru/wp-content/plugins/ ... site10.ru/wp-content/plugins/ Task: YYY directory to copy all directories plugins ...
0
votes
2answers
392 views

Explanations of an Android image build script

I was getting one program for partitioning SD card.I have given that script below: #!/bin/sh if [ $# -lt 2 ]; then echo "example usage: $0 /dev/sdc \$ANDROID_ROOT" exit 1 fi DRIVE=$1 ...
2
votes
2answers
2k views

Displaying a specific date

I'm trying to display a specific date in Unix, using the date command, I can't figure out how to display a date other than today's date. For example, if I was trying to display July 4, 2011 I use $ ...
0
votes
2answers
107 views

Piping commands together in unix

How do I pipe the output of one command to another in unix? For example, If I want to pipe the output of sort to tail, how would I do that?
1
vote
3answers
904 views

Shell script Variable Structure

How can I create a variable with a file name format like : FileName pattern: SnapshotIR__somenumber.csv I tried something like : TODAY=$(date +"%m%d%Y") SNAPSHOT = $(SnapshotIR$TODAY*.csv) I ...
5
votes
3answers
3k views

Create symbolic links to files using wildcards

I want to create symlinks to multiple files: ln -s dev-*.php 's/dev-(.*\.php)/$1/' Results hoped for: site.php links to dev-site.php file.php links to dev-file.php What's the most ...
4
votes
2answers
948 views

Get the complement of the result of an ls command

Let's say I have a directory with multiple files, all of which are either binary files (files with no declared extensions) and source files (.c extension). I do this: $ ls and get: README.md ...
1
vote
3answers
2k views

Extract the base file name from a URL

url=http://www.foo.bar/file.ext; echo ${url##/*} I expected this code to print file.ext, but it prints the whole URL. Why? How can I extract the file name?
0
votes
1answer
745 views

Send email if specified files do not exist

I am new to unix scripting. I have to do something like : In a folder /x everyday 10Pm and next day 3 AM, 2 files are placed. I have to write a script which will check the folder /x and confirm if ...
1
vote
2answers
118 views

Cron creates vim process but does not display vim

Under MacOSX 10.8.2 I am able to run vim as follows in the bash shell: /usr/bin/vim -c "normal G" -c 'startinsert' ~/.journal If I put the exact same command in a script: #! /bin/bash export ...
1
vote
0answers
190 views

(KDE or X ) Script opens konsole in wrong virtual desktop

I have this script. I put it in ~/Desktop. I view the script on my desktop in a "Folder View" widget. When I click on the script, I get list of users, then I get an authorization dialog box ( for a ...
1
vote
1answer
2k views

How to match 2 large file and print the difference in shell script

I have 2 files. File1 has 400k numerical records. e.g: 1 2 3 4 5 6 .. and so on File 2 also has 420k numerical records. e.g: 1 2 3 4 6 .. and so on Both these file are in unsorted manner. I want ...
3
votes
8answers
4k views

grepping dotfiles with -R correctly?

From time to time I need to find a culprit in an unknown dotfile and instead of trying to figure out which package is to be blamed (e.g. xfce4 or thunar?) and what is their naming convention (.app vs ...
2
votes
1answer
2k views

How does wc -l `ls` give the actual number of lines?

Can anyone explain to me how does this command work. wc -l `ls` while this command gives the total number of java lines or txt lines.
5
votes
1answer
8k views

how to compare two xml files having same data in different lines?

I have two files have same data but in different lines. File 1: <Identities> <Identity> <Id>048206031415072010Comcast.USR8JR</Id> ...
4
votes
2answers
2k views

What's a safe and portable way to split a string in shell programming?

When writing a shell script, I often want to split a string. Here's a very simple example: for dir in $(echo $PATH | tr : " "); do [[ -x "$dir"/"$1" ]] && echo $dir done This will ...
6
votes
3answers
1k views

Tar piped to split piped to scp

So I'm trying to transfer a bunch of files via SCP. Some of these are too large to be stored on the recipient (Android phone, 4GB file size limit). The sender is almost out of space, so I can't ...
3
votes
5answers
277 views

Regex match in CLI

Is there something like a logical for the cli? I want to achieve this mv -t newfolder *.(png|jpg) so that alls jpg and png files are moved into newfolder. I know it could be done with mv -t ...
3
votes
4answers
1k views

Unix - how to fetch files based on the part of a filename that is date

Say I have files say like AA_XX_20111208 AA_XX_20111207 AA_XX_20111206 AA_XX_20111205 AA_XX_20111204 AA_XX_20111203 So using the date part, how can i fetch previous 2 month files ? For e.g. this ...
1
vote
2answers
434 views

How to move files from one directory to a nested directory using SSH?

I'm new to SSH. I would like to know how to move all the files, not the folder or directory, to an existing folder or directory two levels down.
9
votes
1answer
29k views

How to create bootable flash for “efi-shell”

Current Intel server chipsets include a built-in "efi-shell" which appears to basically be a simplified 'NIX with a command set suitable for manipulating some nifty UEFI boot options. It is also the ...
3
votes
2answers
817 views

Can the shell warn me if a program is waiting for standard input?

Let's say I want to search for a string in a big file: grep foo bar.txt | less, but I actually type grep foobar.txt | less. Now, grep is waiting for me to type something on the terminal. It appears ...
1
vote
2answers
109 views

Reduce redundant logfile

I often have longer redundant log files, redundant in the sense that blocks of text repeat with minor changes. The length of the files makes it difficult to spot the actual information. I had the idea ...
2
votes
2answers
3k views

How to remove element from the list?

I have written a command that output a list of hostnames, e.g. : clab148node11 clab148node12 clab148node15 clab148node16 Now, I would like to remove those nodes that do not respond to ping. For ...
1
vote
1answer
4k views

What does sourcing a file mean in a shell? [duplicate]

Possible Duplicate: Different ways to execute a shell script What happens when I issue the following command: source devenv.csh How does it differ from running it just as devenv.csh ?
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votes
2answers
28k views

Redirecting the content of a file to the command “echo”

I have a file named my_file.txt whose content is just the string Hello. How could I redirect its content to the command echo? I know I have the commands less, cat, more... but I need to do it with ...
4
votes
2answers
7k views

What is the difference between ping -w and ping -W?

What is the -w (deadline) flag in ping for? I cannot find a description of it in the ping man page; only for -W, which takes seconds as a parameter. What is the difference between them, and how can I ...
2
votes
4answers
20k views

How to send many commands to shell and wait for the command behind ends

Hello I have around 20 commands and I have to send all of this to Unix shell, and copy the result, but I don't know how to do it. I am not sure about what shell I have, because it is a small program ...
7
votes
2answers
14k views

Good method to compare time?

I need to check for the current time and abort the script if it is not proper time of day I am supposed to run it. Also, if anyone else runs it, it should abort. For example: I need my script to only ...
0
votes
2answers
1k views

Comparison of shells? [closed]

Do shells have any actual advantages or disadvantages? They can all run any binary, they all support pipes and > (output to file). Why would one choose bash over sh, or sh over ksh, etc? Why does ...
1
vote
1answer
120 views

How get program name that produced an IO error redirected to a LOG in a nohup command?

I have a program that executes other programs in the background. The main program would be programA, and the programs executed by the main one, would be program1a, program1b and program1c. I need the ...
2
votes
3answers
2k views

Linux Shell Script - Send command over TCP to Sharp Aquos

I'm writing a shell script that needs to send an 8 character string terminated with a x0d to a Sharp Aquos TV. An example is 'POWR1 \x0d' (POWR1 followed by three spaces and LF) The documentation ...
1
vote
1answer
1k views

Outputting last modification date to another file?

I'm trying to read the number of lines in a file, and the last modification date of that file (e.g. if it was last modified Jan 18, 2013, it should output 2013-01-18), then append the data to the ...
3
votes
1answer
242 views

Passing all files of specific filetype in current and subdirectories

I have constructed an elaborate 500+ character command with many arguments and switches to autosign multiple PDF documents. I'm using JSignPDF and I'd like to use it's batch mode including the ...
3
votes
3answers
3k views

How to execute a bash script on multiple directories?

I have a conv.sh script that loops over MP3 files in the current directory and converts them into OGG. I have also several directories {F1, F2,..., F20} at /path/to/Files/. How should I execute ...
1
vote
3answers
1k views

Finding lists of files with specific permissions

I looked into the find command and came up with find . -maxdepth 1 -perm 521 > test.txt to output the permissions to a text file, but is it possible to do it just using, for example, simple ...
8
votes
2answers
321 views

Difference between [[ $variable ]] and [[ -n $variable ]]?

In bash, are [[ $variable ]] and [[ -n $variable ]] completely equivalent? It appears to be the case judging by the output below, but I see both forms of usage prevalent in shell scripts. $ z="abra" ...
3
votes
4answers
1k views

What are commands to find shell keywords, built in functions and user defined functions?

I was discussing with my friend on how the commands are parsed in the shell, and he told me that bash searches the command in following order List of aliases List of shell keywords List of ...
3
votes
1answer
887 views

Why does sendmail work differently in different shells?

The following code works when I directly run it in bash shell: SUBJECT="SUBJECT-"`date`; MAIL_FROM="abc@site.com"; MAIL_TO="abc@site.com"; MAIL_CC="abc@site.com"; MAIL_FILE="/path/of/html/body.html"; ...
8
votes
4answers
2k views

mkdir -p for files

mkdir -p will create a directory; it will also make parent directories as needed. Does a similar command exist for files, that will create a file and parent directories as needed?
3
votes
5answers
566 views

Copy Sequential Files

I have 12 files named dmp_000, dmp_001, etc, all the way to dmp_011. I would like to copy all of them to rdmp_000, rdmp_001, and so on, sequentially so the numbered files coincide. There must be an ...
3
votes
4answers
5k views

How to pipe the stdout to a file if the current command is already being piped through gzip

So I have this command I need to run then disown: innobackupex-1.5.1 --user=root --password=**** --stream=tar ./ | gzip - > /data/myfile.tar.gz How do I pipe any output to a file? adding ...
7
votes
3answers
570 views

OpenSSH - map aliases in ~/.ssh/config to IP addresses in command line

Is it possible to query ~/.ssh/config in the command line? Let's say I would like to retrieve what IP address does the particular alias point to in a separate program, is it possible?