one or a set of directive issued in the *nix environment to get information, change state of something or to execute something; in other word to gain an objective.
3
votes
1answer
30 views
How to update 'command cache' after change of soft links?
I have changed multiple soft links on my system with ln -f -s. When I view the link with ls -l, I see they point to the right target.
However, when I try to run the command, it still tries to use the ...
0
votes
2answers
15 views
How to format the output of free/sar/such commands?
I need to get some specific columns from the output of free command, the way I'm following doesn't seem good, could anyone please suggest me a better way?
bash-3.2$ free -gotsi
...
27
votes
5answers
659 views
How to save a command you entered without executing it? [duplicate]
Every Linux user has experienced this annoying thing: you begin typing a long and boring command, then realise you should have executed another one before. How to save the first one to execute it ...
3
votes
4answers
50 views
Generate random numbers in specific range
After googling a bit I couldn't find a simple way to generate with a shell command a random number included in a specific range, between a minimum and a maximum.
I read about /dev/random, ...
0
votes
1answer
36 views
How to save mails in Unix? [closed]
I wanted to save mail in unix in some directory, as we do in outlook (files are saved with .msg extensions). Is there any workaround for doing this.
1
vote
1answer
13 views
Multiple MODULEPATH entries in .modulesbeginenv
I'm switching between paths/code projects. At each place I have different modules. To handle this there is a setup script that modifies what to use. This is handled with the tool 'module'.
NOTE: ...
21
votes
4answers
1k views
Is the shell permitted to optimize out useless terminating commands?
If a shell is asked to perform a probably useless (or partially useless) command known to terminate, such as cat hugeregularfile.txt > /dev/null, can it skip that command's execution (or execute a ...
8
votes
3answers
337 views
Vim: pasting lines line by line
Let's suppose I have a file containing:
xxx
yyy
zzz
and another file:
kkk
qqq
ppp
I want to obtain:
xxxkkk
yyyqqq
zzzppp
Is that possible in Vim with some command? (I've tried using VISUAL ...
3
votes
1answer
34 views
Printing short latex snippets
Is there a way to quickly (render and) print short latex snippets like single equations?
Something similar to
echo "Some text" | lpr
like
make-latex-image "$\frac{some}{equation}$" | ...
5
votes
1answer
53 views
What's the difference between “realpath” and “readlink -f”
I've read a lot about realpath command and how it has been deprecated with the readlink -f being now recommended. I have also seen in some places that the reason why realpath was introduced was for ...
7
votes
3answers
406 views
Difference between sudo -i and sudo su [duplicate]
I was wondering what the difference is between sudo -i and sudo su?
0
votes
1answer
189 views
Does Linux allow executing the “rm -rf / ” command? [closed]
We all know that we have to use the -rf option of rm command carefully. What I wonder is does Linux allow executing this command: rm -rf /?
If so, why? This command could have disastrous ...
7
votes
2answers
257 views
Change the order of executables started in bash
If I execute the test command in bash, test(evaluates conditional expression) built-in utility is started:
$ type test
test is a shell builtin
$ type -a test
test is a shell builtin
test is ...
1
vote
4answers
183 views
List all commands that a shell knows
What can I type at my shell (which happens to be bash) that will list all the commands that are recognized?
Also, does this differ by shell? Or do all shells just have a "directory" of commands they ...
5
votes
1answer
370 views
What exactly are commands? How to identify? [duplicate]
I want to know what exactly are Linux commands? & how to identify and locate them?
6
votes
4answers
123 views
Is there a tool for summarizing what all commands do?
So I understand that there are man pages for getting the documentation when the internet is unavailable, or when you need advanced uses, but what if I'm offline and I don't even know what tool I need ...
4
votes
3answers
1k views
Difference between 'ifconfig' and 'ip' commands
I read some articles/tutorials on 'ifconfig' command, most of them included a common statement -
"ifconfig is deprecated by ip command"
and suggested to learn ip command. But none of them ...
2
votes
2answers
69 views
Tool for viewing top N items in stream
I'm looking for an existing Linux command-line tools that can accomplish the following:
Consider there is an input stream /dev/inputstream which spews an infinite stream of data that looks like this:
...
1
vote
1answer
43 views
How to convert .doc to ODF with a command line?
I'd like to convert many Microsoft Word documents to ODF (the OO.org formata with a command line (because there are many of them).
(I need them for reading afterwards on a device where reading OO.org ...
0
votes
3answers
4k 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 ?
0
votes
0answers
176 views
Pbrun not allowing to execute commands
why do i get this when i execute pbrun.
$ pbrun ls
You are NOT allowed to use pbrun -h <remotehost> ls.
Please try again without -h option.
Host: xxxx
Submithost: xxxx.abcd.xyz.com
...
2
votes
4answers
464 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
2answers
239 views
Redhat Linux: How to know my system configuration?
I am using Red Hat Enterprise Linux Server release 5.9 (Tikanga).
For installation of any application, it is very important to know the system configuration, is it 32 bit or 64 bit system, Installed ...
1
vote
1answer
165 views
What is the extended version of the “sl” command?
Recently I've been discussing Unix humor with a friend and we got to the topic of the sl command. I got the sources, compiled, installed on our development machine, and... got rather disappointed. The ...
5
votes
2answers
259 views
Get the actions for a command programmatically
Let's take the git example:
$ git<TAB><TAB>
git git-import-dscs git-shell
git-buildpackage git-import-orig git-upload-archive
git-dch git-pbuilder ...
80
votes
3answers
7k views
Why is “echo” so much faster than “touch”?
I'm trying to update the timestamp to the current time on all of the xml files in my directory (recursively). I'm using Mac OSX 10.8.5.
On about 300,000 files, the following echo command takes 10 ...
1
vote
1answer
78 views
`tar` with `find` with removing original file extension
I want to create tb2 files from bunch of text files like this.
tar cfj $(basename ./2014_04_09.txt .txt).tb2 $(basename ./2014_04_09.txt)
With this command I can create a archive file 2014_04_09.tb2 ...
11
votes
7answers
2k views
-3
votes
1answer
40 views
In what directory can I find the list of terminal commands or the set of scripts that give each one its purpose/power?
Is it hidden or accessible?
Also, can you create a new script and define a new command to execute system-wide by adding it to this directory and giving it the same privileges?
3
votes
5answers
195 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 ...
1
vote
2answers
18 views
Install-on-Demand Wrapper Function for Executables
How do I make the following function work correctly
# Install git on demand
function git()
{
if ! type git &> /dev/null; then sudo $APT install git; fi
git $*;
}
by making git $* ...
5
votes
3answers
2k 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 ...
1
vote
1answer
44 views
How to start an application as GNOME would by command line?
How would I start an application (by launcher) the exact same way as GNOME would, in a command line interface? I want to set some environment variables.
I know I can check the launcher file for the ...
0
votes
1answer
32 views
Is there any command to list all related files and folders to specified file in macosx?
I have many ctags in my macosx. When doing which ctags, it gave me /usr/bin/ctags.
But I also want to know where is all related folders and files to this /usr/bin/ctags
Any useful command?
15
votes
2answers
486 views
Is there something like `time` that also records I/O and CPU?
I can pretty quickly monitor the running time of a process with time:
x@y ~ $ time foo
real 0m14.299s
user 0m4.770s
sys 0m0.440s
Is there a way I can get the same data for ...
1
vote
1answer
32 views
Escaping dash in `dch` call
I'm using dch to modify the changelog for a debian package that is being built using some bash script. The messages for changelog are taken from some data source and are just passed to dch --append.
...
1
vote
2answers
134 views
How to get SCP execution time in milliseconds?
I have a script in which i am reading source and destination IP address from a csv file and recording the time in milliseconds it is taking to copy the file from source to destination (using scp).
...
25
votes
2answers
5k 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?
0
votes
3answers
81 views
Remove extra line break from a variable
I am an absolute newbie to the *ix ,so if my question is dumb please bear with me.
I am writing a script where I am trying to export some variable , and after exporting my variable when I am printing, ...
4
votes
2answers
336 views
Command completion does not complete the files in the current directory
Something is wrong with my tab completion.
Let's say I do this:
cd test // works fine, go into test directory
ls // works fine, displays all of the files
Let's assume I have the following files:
...
20
votes
2answers
608 views
How do I move all files output from a command?
I have this grep command to find files without the word Attachments in them.
grep -L -- Attachments *
I want to move all the files that are output from that command. How do I do that in bash? Do I ...
-1
votes
3answers
57 views
How to know in which distribution is present one command [closed]
How can I know the Linux distribution of the command?
For example, lscpu command
Is there any place with a matrix (distribution, commands)?
2
votes
2answers
64 views
netstat command doesnt work anymore on the new dedicated server
I was using the following command on my previous dedicated server with the same version of the FreeBSD installation:
# uname -a
FreeBSD 9.2-RELEASE FreeBSD 9.2-RELEASE #0 r255898: Thu Sep 26 22:50:31 ...
2
votes
2answers
294 views
How can I restore file timestamps of video recordings using the embedded metadata?
I'm looking for a command that will read the metadata of a ‘*.mp4’ file and touch the file's timestamp with the creation time of the video. The command should be read-only with respect to the file ...
2
votes
1answer
15 views
Retrieve system commands without reading sources
Sometimes I wonder how Linux programs achieve certain results knowing that they internally use system calls (system() or exec() in C programs). Given a working binary I wonder if it is possible to ...
1
vote
1answer
103 views
Command to Download Source Files in FreeBSD
In most Linux distros there is a command sometimes the same one used to install or build (compile) packages with extra switch; which just download the source files instead of building or installing ...
1
vote
1answer
255 views
How can I pipe commands to any terminal?
I often use more than one terminal (or terminal emulator) at a time; and while in X I can copy-paste commands, besides not being very practical, it obviously does not work on the real TTY. The first ...
3
votes
3answers
281 views
Shortening build command
Is there any way I can shorten this openCV build command?
g++ file.cpp -o newFileName `pkg-config --cflags --libs opencv`
I tried adding:
-o newFileName `pkg-config --cflags --libs opencv`
to an ...
0
votes
0answers
46 views
No such process error with launch ctl start. Mac OSX 10.9
The goal is to set the machine's network name with the IP address of this machine.
I have created a plist file and put it into /library/launchagents/. For debugging reasons, I used the commandlaunctl ...
0
votes
2answers
104 views
How do I get the list of exit codes (and/or return codes) and meaning for a command/utility?
Is there a way I can do what stated in the title from the terminal commands, or will I have to look into the codes?
