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.
0
votes
0answers
21 views
want to replace a file data from another file [duplicate]
I want to replace a file data from another file
Suppose file1 have data written below and file2 have some data i want to store replace file1 data from file2 from starting word // +++ CUSTOMIZATION ...
0
votes
2answers
17 views
to get process id [on hold]
We need to run a second command until first command finishes. We've tried the following commands:
#1
pid =!$
wait pid
#2
pgrep bsub
wait pgrep bsub
For both of these commands we are getting ...
1
vote
2answers
56 views
How to kill all processes for a given user that take longer then X time
When I list processes with ps auxf I often see some that are stuck and I need to manually kill them. How can I do it with one command?
Example ps result:
$ ps auxf
USER PID %CPU %MEM VSZ ...
18
votes
4answers
1k views
The difference between -r and -R
It often happens that I want to apply an operation recursively. Some commands, such as grep, use a lowercase r to indicate recursion. For example
grep -r foo .
Other commands seem to prefer an ...
0
votes
0answers
25 views
calling system(“command”) from signal handler [migrated]
In a signal handler, I saw system() used to invoke some shell commands, like
void
sig_handler(int signum) {
system("command1");
system("command2");
system("command3");
signal(signum, ...
1
vote
3answers
58 views
What is the concept hidden behind the term “command”?
I have been using, studying and developing for Linux for quite a few years now, and over time, I have successfully convinced a few people to join the cause, and make the switch to Linux.
However, ...
2
votes
1answer
31 views
Command to print few consecutive lines from middle of a file [duplicate]
For a file containing 20 lines, lines 6-10 can be printed using following command:
head -10 filename | tail -5
Can this exactly same thing be done without using 'head' and 'tail' commands ??
...
0
votes
2answers
42 views
execute command from txt file
I have file and in this file i have this lines:
ssh [email protected]
ssh [email protected]
etc....
And i have script that i like to go on every server and execute the ls command on each of this ...
1
vote
0answers
31 views
Edit a command? [duplicate]
I'm using many basic commands of unix/linux. In Mac OS X Mavericks, I type cat for a file, but output was faulty.
In example, content of the file named bar:
foo
bar
Then:
...
2
votes
1answer
45 views
What is a command that will only show me the command syntax and options?
Is there a command which will just list all the options for a given command on one or two lines and not as long and words as man or info ?
9
votes
6answers
1k views
How do you remember command options? [closed]
I am curious to know what trick you use to remember options for various commands? Looking up man pages all the time is time consuming and not so cool!
0
votes
2answers
37 views
`cron` service and `at` command
Help to understand: is there any relation between cron and at command.
Actually if I stop the cron services in SUSE by running following command:
/etc/init.d/cron stop
after above, if I run at ...
1
vote
3answers
152 views
1
vote
3answers
85 views
How to rename file using substring of the same file name [duplicate]
I want to rename my file with its substring.Because unfortunately renamed all the files in my server.
Now I want to remove suffix( .gz) of all the files including files in subdirectories also.
Below ...
4
votes
1answer
1k views
ifconfig command not found
I've just installed CentOS7 as a virtual machine on my mac (osx10.9.3 + virtualbox) .Running ifconfig returns command not found. Also running sudo /sbin/ifconfig returns commmand not found. I am root. ...
1
vote
0answers
52 views
alias Not able to execute source command
I am trying to define a following alias in my .aliases file.
alias sett 'cleartool setview viewXYZ_!*; cd /path_dir1/dir2/; source ./env/script-name'
I use it as sett myview on commnd prompt when I ...
3
votes
1answer
40 views
Switching users without the - symbol
I had to switch to a different user earlier for something that I was working on. I have originally done:
su support
While I was successfully able to switch to support, I found I was unable to make ...
1
vote
0answers
97 views
ssh from an unix server to a windows server (running Sysax) fails
We are doing a sFTP from an Unix server to a Windows server and also a ssh, from the Unix server to the Windows server, to execute a file present on the Windows server.
These 2 steps worked well.
...
3
votes
1answer
20 views
How to execute as the logged-in user in a sudo script (OSX)?
Is there a way to switch contexts like that?
The script in my specific case is an installer postinstall script, which requires sudo privileges only for some of the tasks and requires the logged-in ...
4
votes
1answer
46 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 ...
3
votes
4answers
130 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, ...
29
votes
5answers
748 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 ...
0
votes
1answer
44 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
50 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: ...
6
votes
1answer
176 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 ...
8
votes
3answers
400 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
3k 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
287 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 ...
5
votes
1answer
378 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
130 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 ...
2
votes
2answers
164 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:
...
2
votes
1answer
63 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
0answers
726 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
...
3
votes
2answers
348 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 ...
5
votes
2answers
304 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 ...
1
vote
1answer
126 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 ...
83
votes
3answers
8k 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 ...
-3
votes
1answer
43 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?
11
votes
7answers
2k views
1
vote
2answers
26 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 $* ...
1
vote
1answer
80 views
How to start an application as GNOME would by command line?
How would I start an application (by launcher) the exact same way as GNOME would, in a command line interface? I want to set some environment variables.
I know I can check the launcher file for the ...
0
votes
1answer
41 views
Is there any command to list all related files and folders to specified file in macosx?
I have many ctags in my macosx. When doing which ctags, it gave me /usr/bin/ctags.
But I also want to know where is all related folders and files to this /usr/bin/ctags
Any useful command?
3
votes
1answer
39 views
Printing short latex snippets
Is there a way to quickly (render and) print short latex snippets like single equations?
Something similar to
echo "Some text" | lpr
like
make-latex-image "$\frac{some}{equation}$" | ...
15
votes
2answers
512 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
35 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
206 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).
...
0
votes
3answers
123 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, ...
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 ...
4
votes
2answers
431 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
710 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 ...
