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
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2answers
2k views

Changing tmux .bash_profile behavior

I have a script in my .bash_profile that prompts for X sessions to boot. When I launch tmux, I get this prompt that I had only intended for the TTY login. Is there something I can put in ...
0
votes
3answers
917 views

Proper place to put shell prompt(PS1) when use sh/bash/zsh together

I'm using dash(sh) or bash or zsh. If possible, I would prefer to put in common place. I want to put proper PS1 settings when I interactive with shell, so these situation should be considered login ...
5
votes
1answer
318 views

Can I add to my groups in the current (shell) process? [duplicate]

If I add myself to a group, it applies only to newly launched processes. Actually it's more restricted than that; it seems to apply only to new logins. I'm not sure what the exact mechanism is, but ...
2
votes
1answer
357 views

Can I transfer running process from dead ssh [duplicate]

Possible Duplicate: How can I disown a running process and associate it to a new screen shell? I have started (as expected) a long copy process from ssh shell (putty) which died due to ...
2
votes
2answers
131 views

How to supress the display of previous job details?

When I run a process in the background the process ID gets displayed in the command prompt. For example: $ gvim 1 & [3] 9584 Now when I run another process the state of the previous one also ...
2
votes
2answers
146 views

What does this syntax mean “${i%.avi}.mp4” [duplicate]

Possible Duplicate: How do ${0##*/} and ${0%/*} work? I have encountered this type of syntax somewhere on the web : for i in *.avi do ffmpeg -i "$i" "${i%.avi}.mp4" done how does ...
2
votes
3answers
1k views

What's the difference between these ways of accessing the shell?

From what I know it seems that there are many ways to access the shell on Linux. So far the methods I know are: To use a program such as Terminal or Konsole To use the shortcuts CTRL + ALT + F1-6 To ...
1
vote
2answers
3k views

How to correctly concatenate strings in shells script?

I have a bash shell which I need to modify, and I have to set a variable in a script and then call another script. My variable, EXTRA_JAVA_OPTIONS must be -javaagent:myagent.jar="-d 0 -i 1000 -l log2 ...
1
vote
5answers
968 views

Rerunning the same command with a different parameter

I know that I can run the following command ls Some{File,Folder} And it is equivalent to running this: ls SomeFile SomeFolder (I also use it a lot for things like mv place_{a,b}) However, I was ...
2
votes
2answers
617 views

Get total size of jpeg images per directory in each directory containing jpegs

I'm trying to get a per-directory total size of all the .jpg/.jpeg images in each directory that contains such images. And showing the full directory path. I'm no bash expert but I've managed to ...
9
votes
3answers
10k views

How to defer variable expansion

I was wanting to initialize some strings at the top of my script with variables that have no yet been set, such as: str1='I went to ${PLACE} and saw ${EVENT}' str2='If you do ${ACTION} you will ...
3
votes
2answers
690 views

Use variables in find command

mount |awk '{print $3}' --> list of mount points find "list of mount points" -name "aaa" -print How can I redirect the result from previous line into find command as searching directory? I would ...
0
votes
2answers
4k views

variables in find command and more shell problem [duplicate]

Possible Duplicate: Recursive rename files and directories I wrote the following script: #!/bin/bash SAVEIFS=$IFS alias export='export' IFS=$(echo -en "\n\b") find $1 -name "*" ...
3
votes
1answer
965 views

Need to improve urlencode function

I need a way to URL encode strings with a shell script on a OpenWRT device running old version of busybox. Right now I ended up with the following code: urlencode() { echo "$@" | awk -v ORS="" '{ ...
6
votes
4answers
9k views

How to use a variable as part of an array name

I have two arrays: arrayA=(1 2 3) arrayB=(a b c) and I want to print out one of them using a command line argument, i.e., without any if else. I tried a few variations on the syntax with no ...
17
votes
1answer
724 views

How does “man” restore the screen when I quit the program?

If I open a man page of a program like cat or ls, it prints (may not be the appropriate word) the contents of the man page and when I press q, it shows the screen just like before invoking the man ...
1
vote
2answers
1k views

What is wrong with this call to sed -i?

I have this line find . -type f \( ! -name '*.plist' \) -and \( ! -name '*.mp4' \) -and \( ! -name '.DS*' \) -print0 | xargs -0 sed -i 's/AAA/BBB/g' my intention is from the current directory ...
8
votes
2answers
6k views

Manipulate file name piped from find command

I'm relatively new to Bash and am trying to do something that on the surface seemed pretty straightforward - run find over a directory hierarchy to get all of the *.wma files, pipe that output to a ...
3
votes
3answers
9k views

Check whether files in a file list exist in a certain directory

The runtime arguments are as follows: $1 is the path to the file containing the list of files $2 is the path to the directory containing the files What I want to do is check that each file listed in ...
10
votes
5answers
5k views

Why is the terminal case-sensitive?

When I do - CD .. instead of cd .. it gives me error saying - CD: command not found Why is the terminal case sensitive when it comes to linux commands? I mean you should be able to execute the ...
3
votes
3answers
888 views

execute shell script options

I typically use cd Directory/Directory/ to point to the shell directory and then type bash shell.sh, but I was wondering if there is an easier way to execute my shell & the location with one line? ...
4
votes
2answers
3k views

How to make cd arguments case INsensitive?

Sometimes while accessing the various directories it happens most of the times that I remember the names or at least part of the names of a directory under our Linux system. But some of the ...
5
votes
2answers
16k views

do…while or do…until in POSIX shell script

There is the well known while condition; do ...; done loop, but is there a do... while style loop that guarantees at least one execution of the block?
6
votes
3answers
909 views

bash: escape individual lines from `-x` echoing

In bash, when running with the -x option, is it possible to exempt individual commands from echoing? I'm trying to make the output as neat as possible, so I am running certain parts of my script in a ...
3
votes
2answers
510 views

create pseudo shell for a command

I feel like this should be straighforward to some degree... Basically, for some command, I want to be able to invoke another command that will scope all params to that command. so... git commit -am ...
6
votes
2answers
3k views

Bash function not working in Zsh

I have been slowly migrating from Bash to Zsh and have got to the point where everything I have moved across is working well, with one exception. I have a couple of functions in my .bashrc that I use ...
2
votes
1answer
216 views

Does each user get his/her own tty(s)?

I put a simple echo command in a CLI tty by user1 expecting it to reach user2 who is logged in a separate tty. echo "Hello, world!" >> /dev/tty5 I expected user2 to get the echo message but ...
1
vote
1answer
1k views

run 'service php5-fpm restart' without using sudo

I am integrating my cakephp projects using jenkins. Right now, I am exploring the use of Phing. There is one task where I need to run service php5-fpm restart So far I tried to do this manually. ...
1
vote
1answer
1k views

Arch linux booting into rescue shell by default

I just installed Arch in my PC alongside windows 7 but for some reason it boots directly into the rescue shell, this is how it looks It doesn't show any errors though, and if I press Ctrl+D it just ...
8
votes
1answer
526 views

What should interactive shells do in orphaned process groups?

(Re-posting in unix per the suggestion in http://stackoverflow.com/questions/13718394/what-should-interactive-shells-do-in-orphaned-process-groups) The short question is, what should a shell do if it ...
3
votes
2answers
752 views

Run shell scripts through a website

I have been reading and searching on what is the best way to run my shell scripts through a website. My goals are as follows: Browse a folder Select folder or contents onclick will run script ...
5
votes
2answers
4k views

How to continuously take backup of log files?

I have some applications in Linux which create log files of around 41 MB each. The application switches from log.1 to log.2 and starts overwriting log.2 once this 41MB is completed in log.1 file. I ...
2
votes
1answer
3k views

Bash restricted Shell using rbash

I am using /bin/rbash for some users. It's working as expected but there is some hack like when users run bash or dash, then they got unrestricted shells, so to avoid these commands, I have added ...
0
votes
1answer
2k views

What is the .screenrc file for?

What is the .screenrc file for? I have seen it in some dotfiles repos and such but I don't quite understand what it's for. Judging from the name it sets settings for the Terminal itself, not the ...
2
votes
4answers
219 views

store and execute redirection/piped command in script

How do you store, and later execute, a command with redirection and and a pipe? (And is it the pipe, or the redirection, or both, that's causing my problem?) I tried to print the urxvt version in a ...
3
votes
2answers
3k views

Can the UNIX command tree display only directories matching a pattern?

I'm trying to figure out if there is a way to get the UNIX command tree to display only directories that match a specific pattern. % tree -d tstdir -P '*qm*' -L 1 tstdir |-- d1 |-- d2 |-- qm1 |-- ...
0
votes
2answers
1k views

Can the UNIX command tree display only directories matching a pattern?

I'm trying to figure out if there is a way to get the UNIX command tree to display only directories that match a specific pattern. % tree -d tstdir -P '*qm*' -L 1 tstdir |-- d1 |-- d2 |-- qm1 |-- ...
1
vote
1answer
72 views

deal with file names with “-” as beginning on linux [duplicate]

Possible Duplicate: How do I delete a file whose name begins with “-” (hyphen a.k.a. dash or minus)? I'm using linux I have some files with file names like -0fdlfld -xfifd I want to ...
2
votes
2answers
224 views

Does a parent bash script remember the cd history from a child bash script?

Example: mainscript.sh cd /mnt/something ./buildscripts/000-script.sh 000-script.sh cd /mnt/otherthing mkdir something exit
2
votes
2answers
911 views

Is there any way to test out PS1 Bash Prompts before committing them?

I'd like to mess with my Bash prompt, but I'd like to do so in a way that doesn't corrupt my already extant one. I could just comment it out, but is there a way to test it either with an online tool ...
0
votes
1answer
164 views

Why is this variable not getting passed to awk? [duplicate]

Possible Duplicate: external variable in awk How do I pass this variable below? This doesn't work: fname=testfile.txt lsof | awk '/deleted/&&/$fname/ {print $4}' *----no output* ...
7
votes
1answer
3k views

recovering deleted file held open by apache?

Suppose an apache log file gets deleted but it's held open by apache; then this is what I am doing: pid=$(lsof | grep text.txt | awk '/deleted/ {print $2}') fd=$(lsof | grep text.txt | awk '/deleted/ ...
1
vote
1answer
1k views

Where to find printf formatting reference?

Where is the offline reference of the format specifiers (e.g., %i, %s) which are supported by the Bash/system printf command? I've looked in help printf, man 1 printf and man 3 printf without luck. ...
8
votes
7answers
5k views

Assigning IP address to environment variable [duplicate]

How can I assign the IP address of eth0 to an environment variable, say $ip, as easily as possible? Update: Distro is Ubuntu Server 12.04 LTS.
1
vote
1answer
152 views

Standard solution for displaying messages either on shell or with window managers gui

Is there a standard solution to display messages from within bash scripts eiter on the commandline if the shell is a login shell or in a new window in the present window manager's GUI? Specifically I ...
6
votes
2answers
20k views

Compress old log file into single zip-linux

I have a folder /home/testuser/log which contain log files of one day old *.log. I wish to compress all the log files older than one day to a single zip(gzip or tar.gz) and delete the older files. I ...
0
votes
1answer
817 views

difficalty to save traceroute output in shell variable?

I need to filter and store traceroute output in shell variable (array). But I am getting some unusual output. As I try to explain in following lines. My present directory is temp, having some ...
3
votes
5answers
721 views

Search among the content of a large number of plain text files?

I have a directory with 1,242,276 plain text files on my external hard drive. They are totally unorganized with meaningless numbers as their file names. The reason for that is because they were ...
3
votes
1answer
660 views

Split file based on a pattern with leading zeros

I have a book in text format. I would like to split the book into several files where each file contains a single chapter. Therefore I'm using the following command: awk '/Chapter/{i++}{print > ...
3
votes
2answers
4k views

What is the difference between '.' and 'source' in shells? [duplicate]

Possible Duplicate: running script with “. ” and with “source ” I have used both the dot command '.' and 'source' to reload a given rc file (typically to update my environment variables) ...