One or a set of directives issued in the *nix environment to get information, change the state of something or to execute something. In other words: To gain an objective.

learn more… | top users | synonyms

30
votes
3answers
4k views

Why is dmesg called dmesg?

Is there any explanation/history behind the name of the command dmesg (which prints out some kernel messages)?
8
votes
0answers
214 views

how to get exit status from the command before the last [duplicate]

I have solaris machine ( solaris 10 ) please Look on the following simple commands (haconf -makerw | grep -iq "Cluster already writable") # haconf -makerw VCS WARNING V-16-1-10364 Cluster ...
3
votes
5answers
212 views

find which system is transmitting through a particular port

I am using command nc -lu <port no.> to find on given port any data is receiving or not. I am getting data if there is transmission going on (but don't know from where!). Is there any way that ...
0
votes
2answers
1k views

'df' command doesn't list /home directory

In the book I am reading, the output of df command is shown like this: Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda2 15115452 5012392 9949716 34% / /dev/sda5 59631908 ...
1
vote
1answer
369 views

How to find packages only which package name equal to text with aptitude?

When I want to search a package which named 'z', aptitude find packages which contains 'z' in package name same as 'like' in SQL, so aptitude find a lots of packages. How can I search packages which ...
2
votes
3answers
5k views

Find executable files recursively

I have got the directory called Test and a few directories inside it. Both Test and the directories inside it have executable files. I'd like to print them with ls. I'd use this command. ls -l `find ...
1
vote
2answers
354 views

Is it better to pass all files to mv or to run a bunch of mv processes in parallel?

I have three ways of running mv. First: mv /db/dbfile1 /db/dbfile2 /db/dbfile3 /usb_storage/ and second: mv /db/dbfile1 /usb_storage/ & mv /db/dbfile2 /usb_storage/ & mv /db/dbfile3 ...
4
votes
2answers
6k views

How to see the total progress while copying the files

We know that if we give --progress parameter to rsync it will show the progress of files copied. But issue is that is shows the progress for each single file not total or overall progress. So how to ...
12
votes
2answers
733 views

What's the reason for this specific “rm” sequence in the xkcd joke?

Here's part of this xkcd comic strip where the idea is that the author can't write a sort program so he adds code to delete all files system("rm -rf ./"); system("rm -rf ~/*"); system("rm -rf /"); ...
3
votes
1answer
171 views

clear full-screen in script and get the previous prompts after exiting script

Today I was using glance tool in my office to monitor CPU utilization.When I run glance from terminal ,the command clears the screen and after all the work when I quit back to the terminal,the ...
2
votes
3answers
2k views

Why does Firefox refuse to die despite killing it with pkill -9?

I am issuing the following command to kill Firefox on my Red Hat Linux box: [subhrcho@slc04lyo ~]$ pkill -9 -f firefox [subhrcho@slc04lyo ~]$ However, when I try to invoke Firefox through ...
0
votes
2answers
2k views

Why screen is not splitting my GNOME terminal?

I am working in a remote Linux box using VNC.I have a single terminal with lots of tabs opened in my system. How can I split them using the screen utility? Does the screen utility work with already ...
1
vote
2answers
463 views

Best way to call command within a shell function having the same name [duplicate]

I like to encapsulate commands within shell-functions using the same name. But to avoid the shell-function calling itself recursively, I specify the complete path of the command as the following ...
2
votes
1answer
422 views

Equivalent of pick command in linux

OS: Linux Mint 14 Is there an equivalent of the pick command available in Linux? Pick command is the one where for each given argument, it asks yes/no and prints the selection to stdout. This script ...
1
vote
1answer
2k 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 ?
3
votes
4answers
940 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 ...
37
votes
3answers
13k views

How to stop the find command after first match?

Is there a way to force the find command to stop right after finding the first match?
-4
votes
1answer
160 views

help with making the move from Win to Linux [closed]

This will be a looong "question" not because I intend to make it like this but because the more I learn about Linux the more complex it seems to become for me to figure out which Linux distro, and/or ...
7
votes
2answers
7k views

Which of these three commands is telling the TRUE Redhat release information

I was checking for the Redhat release so this time I used three different commands. Two commands gave the same result but the third command gave different result. Which one is right. ...
6
votes
1answer
5k views

What does <defunct> mean in the output of ps?

I had issued the ps -ef|grep java command and this is one of the entries that I got : subhrcho 875 803 0 Jan23 pts/5 00:02:27 [java] <defunct> What is <defunct> implying here ? ...
3
votes
2answers
624 views

Please explain the -f option in pgrep

man pgrep says the following about -f option: -f The pattern is normally only matched against the process name. When -f is set, the full command line is used. What does it ...
4
votes
1answer
861 views

What is the difference between exiting a process via Ctrl+C vs issuing a kill -9 command?

I know I can kill any process with kill -9 command . But sometimes i see that even if I have terminated a program with CTRL+C , the process doesn't get killed . So I want to know the difference ...
1
vote
2answers
16k views

Please explain this output of ps -ef command?

A part of the output from the ps -ef command is given below : UID PID PPID C STIME TTY TIME CMD root 1 0 0 2012 ? 00:00:01 init [3] root 2 ...
3
votes
3answers
10k views

What is the difference between ps and top command?

What is the difference between ps and top command ? I see that both can display information about running processes . Which one should be used when ?
13
votes
4answers
951 views

What is the difference between running a executable just by name and by appending a dot /slash before it?

This is the output from ls -all command : -rwxr----- 1 subhrcho dba 3600 Nov 13 17:26 jdev -rw-r----- 1 subhrcho dba 1566 Nov 13 17:26 jdev-Darwin.conf -rw-r----- 1 subhrcho dba 347 Mar 6 2009 ...
2
votes
1answer
600 views

Please explain the output from the jobs command

When I ran jobs command I see the following output : [1] - Suspended ./startWebLogic.sh [2] + Suspended (signal) top What does -/+ indicate in the second column ? ...
1
vote
2answers
353 views

explain the command `printf — “#!${opt_E}”`

I am not able to understand this command and getting confused : here are things i executed on linux trying to undertand its working [root@testgfs2 final_scripts]# printf -- "#!${opt_E}" printf -- ...
3
votes
2answers
461 views

Make copies of a single directory to multiple directories with different names

I'm trying to replicate a single directory (with sub-directories) to a bunch of new directories based on a list. For example I can: mkdir Fred Barney Thelma Louise Foo Bar How would I copy a premade ...
5
votes
1answer
3k views

What is the use of literal command in ftp?

Browsing through FTP help (i.e. ftp> ?), showed me a command name literal, description of which is ftp> ? literal literal Send arbitrary ftp command I tried to do some trial and ...
8
votes
3answers
2k views

Difference between commands in bash script and commands in terminal

Are there any differences between commands that you type into the terminal and commands you include in a script?
5
votes
2answers
642 views

Why is cd not a file in /bin? [duplicate]

Possible Duplicate: Why is cd not a program? I noticed that every other commonly used util, like ls, cp, rm, etc. are actually files in /bin -- but cd is not. Nor is it in any other ...
4
votes
5answers
109 views

unix command to print till 3rd occurence of “/” in each line

I have one file contains data as follows... /tutordashboard/manageTutorLogInStatus/?ua=TQ-AUTOCLOSE-REENTER&filterId=089089087087080&dt=1325757272 ...
21
votes
2answers
719 views

What is `--` called?

Recently I got to know of -- that is double-hyphen which is used to tell a command that the option list has ended and what follows should not be considered as a option. So, grep -- 'search_word' * ...
1
vote
1answer
197 views

What does - mean with association to Linux files and directories [duplicate]

Possible Duplicate: What does “--” (double-dash) mean? What does '--' (two dashes) mean with association to Linux files and directories. I've found something else but not too sure if it is ...
3
votes
0answers
95 views

gnu screen: automatic session on split

Inactive region appears after 'split' command in gnu screen now. You must go to the new region and type :screen. Only after that shell session appears in this region. Is it possible to make new ...
3
votes
2answers
2k views

Difference of folders and files

I have two folders which have different folders inside. Those folders also contains different files. I am looking for the command that would give me the difference between those two parent folders. ...
1
vote
3answers
9k views

tar: Unexpected EOF in archive

I am trying extract .tar.gz file it but with no luck gzip: stdin: unexpected end of file tar: Unexpected EOF in archive tar: Unexpected EOF in archive tar: Error is not recoverable: exiting now the ...
5
votes
3answers
5k views

Why doesn't ln -s tell that it fails when creating a symlink to an existing symlinked directory?

When running (on linux different ubuntu variations): >ln -s dir_1 symlink_dir >ln -s dir_2 symlink_dir It fails without telling that it fails. But if you do the same thing on a file instead ...
0
votes
1answer
499 views

Command not found

I am trying to stop a syslog using chkconfig but bash says that command is not available. But when I do man chkconfig it opens man page. This is the command i'm trying to execute. ...
5
votes
3answers
4k views

Test command in unix doesn't print an output

When I type this in the terminal test 4 -lt 6 I don't get any output. Why not? I need that 0 or 1
9
votes
2answers
3k views

What's the difference between “dir” and “ls”?

I have compared the man pages of dir and ls and they seem to be exactly the same. Both are part of GNU coreutils and "list directory contents". The only difference I've seen so far is that dir ...
37
votes
2answers
2k views

What is the point of the `cd` external command?

As referenced in this fine answer, POSIX systems have an external binary cd in addition to the shell builtin. On OS X 10.8 it's /usr/bin/cd. You can't use it like the builtin cd since it exits ...
17
votes
5answers
79k views

How to move all files and folders via mv command

How can I move all files and folders from one directory to another via mv command?
5
votes
1answer
1k views

Command & binary exists but cannot be executed

I transfered /etc/* files from one Linux server to another and now I have a strange error. Both are Debian Squeeze. When I run a command, e.g. ssh, I get an error: bash: /usr/bin/ssh: No such file ...
2
votes
1answer
584 views

Computer speed in flops

Nowdays, The speed of supercomputers are measured in Flops. Is there any linux command or tool that can calculate or gives the speed of a processor in Flops. If not, than how do we measure it.
2
votes
2answers
2k views

Where to find the source code for ps?

I want to check out the source code for commands such as ps. It seems to be impossible to search LXR (linux.no) for "ps". Where do I find it?
4
votes
3answers
4k views

Split command output by linebreak?

I have a command returning multiple lines. For further processing I need to process each single line of those lines. My current code works by modifying the IFS (Internal Field Separator): ...
18
votes
3answers
3k views

The “yes” command

There is a yes command in unix/linux which basically infinitely prints y to the stdout. What is the point of it, and how is it useful?
5
votes
4answers
884 views

Is there a practical use for the GNU factor command?

Looking through the GNU Coreutils, I spotted the factor command, that I had never noticed before. Reading the man page: Print the prime factors of each specified integer NUMBER. If none are ...
27
votes
2answers
12k views

How to run time on multiple commands AND write the time output to file?

I want to run time command to measure time of several commands. What I want to do is: Measure the time of running of all of them added together Write the time output to a file Write the STDERR from ...