The command-line is the interactive interface to your shell.

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1
vote
2answers
921 views

run script asynchronously / in a different process

I have a simple php script <?php for($i=0;$i<10;$i++){ sleep(1); echo $i; } Which I run from the command line php myfile.php & I would expect I can do other things in the command line, ...
5
votes
3answers
578 views

Shortcut for fast recursive removal

Sometimes I want to delete large swaths of temporary files recursively, and recycle the directory name without waiting for the command to complete. (For example, if I want to nuke and re-checkout a ...
63
votes
6answers
56k views

Is there a tool to get the lines in one file that are not in another?

Is there any tool that can get lines which file A contains, but file B doesn't? I could make a little simple script with, e.g, perl, but if something like that already exists, I'll save my time from ...
2
votes
1answer
171 views

How can I adjust this short shell script to fit my needs?

I am attempting to force powertop to run when I log in by using the Startup Applications wizard in Ubuntu. Under the 'Command' entry, I've placed gnome-terminal -x ...
5
votes
2answers
3k views

the usage of < /dev/null & in the command line

I tried to run an example java program using the following command line. However, I do not know what is the trailing part < /dev/null & used for? java -cp /home/weka.jar ...
24
votes
4answers
4k views

Is it possible to configure ctrl-w (delete word)?

Normally, Ctrl+W deletes back to the last whitespace. Is it possible to configure it to use additional characters, such as /? Edit: To be more clear: I don't want to configure the key for it, I want ...
7
votes
4answers
831 views

pager program like less, able to repeat top N lines

Is there any way to make less program repeat first line (or first 2 lines) on every displayed page? Is there any other pager program which can do this? This would be a killer-app for database table ...
7
votes
3answers
18k views

Running python script from terminal without .py extension

I want to call a python script script.py from the terminal by simply typing script. Is this possible? If so, how? I know I can avoid typing python script.py by adding #!/usr/bin/env python to the top ...
5
votes
4answers
3k views

Delete everything except a few extensions

Can I modify the rm command with regular expression or something to delete. every file in current directory except files with extensions *.bmp, *.wav and *.png? It should be case insensitive because ...
16
votes
4answers
8k views

Why do some commands 'hang' the terminal until they've finished?

Sometimes you run a program from the terminal, say, lxpanel†. The terminal won't drop you back to the prompt, it'll hang. You can press Ctrl+C to get back to the prompt, but that will kill ...
18
votes
3answers
3k views

How can I keep control+d from disconnecting my session?

I regularly ssh to a centos 5 box. Somehow they keys are mapped so that control+d will log me out of my current shell. If I am sudo'ed to another use it puts me back to the previous user. If I am not ...
68
votes
10answers
54k views

How can I edit multiple files in VIM?

I know I can open multiple files with vim by doing something like vim 2011-12*.log, but how can I switch between files and close the files one at a time? Also, how can I tell the file name of the ...
3
votes
1answer
327 views

How to use SCSUDO to run scripts with positional parameters?

I am trying to use scsudo to run a number of defined commands to stop and start processes on a UNIX host. The issue I am experiencing is that scsudo does not seem to like the use of positional ...
2
votes
1answer
195 views

ide and pci bus commands

Is the ide interface also a bus? Is there a command like lspci or lsusb, to find out what devices are on the ide bus? Sources seem to contradict eachother. I'm asking this question here because of the ...
2
votes
3answers
119 views

Filter --help command?

Sometimes I want to search/filter help for particular commands for keywords. history --help gives list of options, sometimes it's overwhelming how much info is there. Can I filter it for keywork ...
1
vote
1answer
217 views

How to create and edit a text file from the bash shell

I am logged into a linux server via ssh. From the bash shell, is there any standard way of bringing up some kind of text editing environment so I can create and edit a text file? I am aware that there ...
4
votes
1answer
313 views

Why did using xargs fail in this case?

I tried to understand the usage of xargs and did the following experiment. ls | xargs | touch I want to refresh the files dates and directoris in the curent directory. Though it is a bit silly,for ...
2
votes
1answer
310 views

How to know if a Linux command can read from STDIN?

I noticed this problem when I became confused with pipe, one command send its executing output to the STDOUT, which is the STDIN for the other command, which can read from STDIN. How do I know if a ...
1
vote
1answer
793 views

How to make festival evaulate its own scheme expressions from the command line, so as to change voices as needed?

I can't seem to find any documentation on this. This forum post shows someone trying to change the voice used by festival, outside of the festival interpreter, using a command-line flag. festival ...
3
votes
2answers
2k views

Passing values through pipes

I don't quite understand pipes in Linux command line. I noticed that: ll - R | grep *.pdf will list files ending with .pdf But locate *.pdf | du -h will not calculate the size of files ...
4
votes
2answers
3k views

What command line tools are available for testing Web Service? [duplicate]

Possible Duplicate: Does anybody here have experience in automating some tasks in web applications using curl? There are a number of GUI based tools to test Web Service (e.g. soapUI) Is ...
3
votes
2answers
101 views

Output the changes to a log file

If I use tail -f *filename* I get a real nice display of whatever is changing in a given file. However, sometimes I want to be able to search this text or otherwise look it over slowly. Is ...
2
votes
4answers
2k views

Access the last file (alphabetically) in a directory

I'm trying to open a file with vim from the command line, the file is in a directory filled with automatically generated files that are prepended with a time stamp. Since I don't know the time stamps ...
2
votes
3answers
320 views

Stuck between these two books? [closed]

I'm new to Unix/Linux platforms so I was hunting for good books on *nix... I soon realized there is not one book or resource. But to gain confidence on the command line and scripting (the real *nix ...
3
votes
0answers
65 views

Use command line to download file which is accessible only in a given session [duplicate]

Possible Duplicate: Does anybody here have experience in automating some tasks in web applications using curl? Sorry for the lengthy title. I am trying use command line to download a ...
4
votes
2answers
751 views

How can I copy all users .bash_history files into my home directory?

I am running as root. I want to copy all the users on the system's .bash_history files into my home directory. I can do this to combine all of them into one, but then I can't tell who's commands are ...
7
votes
1answer
3k views

List of modified files of the past 24 hours

Is there a reliable way to have a system that mails me the list of files that were modified in the past 24 hours inside a set of directories? (like /home/*/public_html/* and /home/*/*domains/*)
2
votes
1answer
351 views

Extract pitch information from audio file

Is there a command-line utility which would allow me to extract pitch information from an audio file and store it in a numerical form (i.e. as a list of comma-separated values)?
19
votes
12answers
20k views

How can I “cat” a file and remove commented lines?

I'd like to know if there is a way that I could cat file like php.ini and remove all lines starting with ; For example, if the file contained this: ; - Show all errors, except for notices ; ...
2
votes
1answer
75 views

App which can execute arbitrary code on different events

I've been looking for a simple activator which can execute some code when stuff happens, I haven't found anything yet. Maybe, I am not using the right keywords. It would be great if someone pointed me ...
20
votes
1answer
8k views

How do I enable locate and queue the database to be built?

On a new Ubuntu 10.4 instance, I tried to use the locate command only to receive the error locate: can not stat () `/var/lib/mlocate/mlocate.db': No such file or directory from using this command ...
5
votes
3answers
1k views

How to create a bounded queue for shell tasks?

I have 1000 gzipped files which I want to sort. Doing this sequentially, the procedure looks pretty straightforward: find . -name *.gz -exec zcat {} | sort > {}.txt \; Not sure that the code ...
6
votes
6answers
312 views

Searching in many files

Is there some sophisticated technique to search strings in many files? I tried this basic technique for i in `find .`; do grep searched_string "$i"; done; It doesn't look much sophisticated and ...
12
votes
2answers
5k views

Is there a unix command line tool that can analyze font files?

Given a directory of font files (TTF and OTF) I'd like to inspect each font and determine what style (regular, italic, bold, bold-italic) it is. Is there a command line tool for unix flavored ...
3
votes
1answer
209 views

Restricting access to files on an external drive

I was wondering how to restrict access to a specific drive in Unix on the Mac. I was thinking to do this in Terminal where I create a file like this mkfile 6k secure_access. And where secure_access ...
19
votes
4answers
16k views

How can I run a specific command for each find result?

How would one run a specific command for each file that was found by using the find command? For the purpose of the question lets say that I would simply like to delete each file found by find. I am ...
11
votes
3answers
4k views

How can I pipe output to another process, but retain the error state of the first process? [duplicate]

Possible Duplicate: Get exit code of process that's piped to another I am using the following command line (in a makefile) to pipe the verbose error messages from my compiler through a ...
0
votes
2answers
7k views

clear tmpfs in my case

I am on a Ubuntu machine. I have make a directory under root directory, by: $ sudo mkdir /hello $ sudo mkdir /hello/bye Then I mount tmpfs with size 1024M to /hello/bye by: $ sudo echo "tmpfs ...
1
vote
3answers
154 views

Transferring access privileges from root to regular user

I log in to Ubuntu with the username student. There are some directories only the root user is allowed to access, for example /var/lib/mysql, (I know I can use sudo to access it but it is not what I ...
0
votes
1answer
12k views

Different ways of using expr command [closed]

I'm trying to learn the bash expr command inside and out. What are some of the most basic to the most creative/tricky/unexpected ways to use the expr command? Small, manageable examples are great.
9
votes
3answers
3k views

Why a long delay after command not found?

Often when I mistype a command such as ls (e.g. I hit ENTER before I type 's') there is a long (~2s) delay after the terminal displays: bash: l: command not found... I can understand the reasons ...
1
vote
4answers
8k views

how to find out the ip of an ssh HostName

Is there a simple way to retrieve the IP of a HostName from an ssh config on the command line? Many times I have to use scp and would like to connect to a machine, but I remember only the HostName.
5
votes
3answers
7k views

Looking for a Java class in a set of JARs with find, unzip, grep

I was trying to find the JAR containing a Java Class. JARs are in zip format. My first attempt was: $ find -name "*3.0.6.RELEASE.jar" | xargs -l1 unzip -l \ | grep stereotype.Controller ...
1
vote
1answer
344 views

Empty typescript file with the script command

In the command line, I typed: script -a myfile Then, I typed the some standard commands. When I opened the myfile using vi, the file was empty. Why is that? And, also, any tips on using the ttyrec ...
9
votes
4answers
1k views

How can I get the most bang for my buck with the “diff” command?

I have tried using the linux diff command in the past without much luck or patience. I usually end up using a GUI utility like DiffMerge or Kdiff. Recently I started trying to use diff again to ...
2
votes
2answers
1k views

How can I make bash more readable? [closed]

As a linux user, I spend a lot of time mucking about in bash. I've always been a bit frustrated by how poor the readability is. Today this annoyed me enough to spur me into action. My immediate ...
8
votes
4answers
622 views

Capturing area of the screen without a Desktop Environment?

I'm running OpenSuse with dwm as a window manager. Since I made the switch from KDE, I haven't found a way to take a screenshot or even capture part of my screen. Is there a way I can do this in a ...
72
votes
6answers
17k views

When is xargs needed?

The xargs command always confuses me. Is there a general rule that can help me figure out when I need it? Consider the two examples below: $ \ls | grep Cases | less prints the files that match ...
1
vote
1answer
568 views

Create recovery medium from Windows 7 recovery partition

Many laptops are delivered with Windows 7 recovery partition (but without CD or DVD) which takes place on the harddrive that could contain some Linux distribution or serve for data storage. I don't ...
26
votes
3answers
18k views

How to execute consecutive commands from history?

Suppose I want to execute a sequence of four commands that I have executed before. If the first one is 432 in the command-history, then I could do: $ !432; !433; !434; !435 I'm curious, is there a ...