Information on this page provides basic commands that you should be familiar with when working within a Linux command line interface (CLI), such as the HPC.
In the examples below, the commands themselves are highlighted in yellow and are followed by the output they produce. Select a topic for details.
ls
: list files in a directory pwd
: show full path to current directory mkdir
: make directories cd
: change directory cp
: copy files and directories rm
: remove files rm -rf
: remove a directory and everything in it man
: show usage manual for a command * ?
and other wildcards ~
: shortcut to your home directory
ls
: list files in a directory
Simple file listing: [abc123@seldon abc123]$ ls
figure1.fig test.m test.sh
Display extra details (file size, type, date, permissions) with the "long" (-l) option: [abc123@seldon abc123]$ ls -l
total 12
-rw------- 1 abc123 users 1121 Oct 30 16:15 figure1.fig
-rw------- 1 abc123 users 69 Oct 30 16:15 test.m
-rwx------ 1 abc123 users 40 Oct 30 16:10 test.sh
You can use wildcards to select only some of the files. [abc123@seldon abc123]$ ls -l test*
-rw------- 1 abc123 users 69 Oct 30 16:15 test.m
-rwx------ 1 abc123 users 40 Oct 30 16:10 test.sh
pwd
: show full path to current directory
Print working directory path: [abc123@seldon abc123]$ pwd
/sscc/home/a/abc123
mkdir
: make directories
Create a new subdirectory called subdir
in the current directory: [abc123@seldon abc123]$ mkdir subdir
[abc123@seldon abc123]$ ls -l
total 16
-rw------- 1 abc123 users 1121 Oct 30 16:15 figure1.fig
drwx------ 2 abc123 users 4096 Nov 4 13:55 subdir
-rw------- 1 abc123 users 69 Oct 30 16:15 test.m
-rwx------ 1 abc123 users 40 Oct 30 16:10 test.sh
cd
: change directory
Switch to a subdirectory called subdir
in your current directory: [abc123@seldon abc123]$ cd subdir
[abc123@seldon subdir]$
Two dots ..
denote one directory up in your path: [abc123@seldon subdir]$ cd ..
[abc123@seldon abc123]$
To use the full path start with a slash: [abc123@seldon abc123]$ cd /datalib/cps
[abc123@seldon cps]$ pwd
/datalib/cps
cp
: copy files and directories
Syntax: cp [options]... Source Destination
cp [options]... Source... Directory
Options:
-i
: prompt before overwriting files -r
: copy recursively (copy subdirectories and their contents) -u
: overwrite destination files only when the source file is newer -v
: show what is being done
Make a copy of a file called make.do
with a different name: [abc123@seldon abc123]$ cp -v make.do make2.do
`make.do' -> `make2.do'
Copy one or more files to another directory: [abc123@seldon abc123]$ cp -v *.do subdir/
`make.do' -> `subdir/make.do'
`make2.do' -> `subdir/make2.do'
Copy the contents of a directory and its subdirectories to another place: [abc123@seldon abc123]$ cp -vR subdir/* subdir2/
`subdir/make.do' -> `subdir2/make.do'
`subdir/make2.do' -> `subdir2/make2.do'
`subdir/data/file.dat' -> `subdir2/data/file.dat'
rm
: remove files
Remove a file called make.do
: [abc123@seldon abc123]$ rm make.do
To remove a file with spaces in its name, use quotes: [abc123@seldon abc123]$ rm "file name.txt"
To remove multiple files (or to save time typing long file names) use wildcards. Be careful - wildcards are powerful and could match more files than you intended. Use the ls
command first to check what files will be deleted. [abc123@seldon abc123]$ rm *.txt
rm -rf
: remove a directory and everything in it
Delete a subdirectory called subdir
and all of its contents (including its subdirectories). [abc123@seldon abc123]$ rm -rf subdir
man
: show usage manual for a command
Display a more detailed manual for a command:
- Press
<Space bar>
to view the next page - Press q to exit
[ate533@seldon ate533]$ man cp
CP(1) FSF
CP(1)
NAME
cp - copy files and directories
SYNOPSIS
cp [OPTION]... SOURCE DEST
cp [OPTION]... SOURCE... DIRECTORY
cp [OPTION]... --target-directory=DIRECTORY SOURCE...
DESCRIPTION
Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.
. . .
* ?
and other wildcards
You can use these powerful wildcards with any command that takes filenames as an argument. For example prog??.*
will match all files with names that start with prog
followed by any two characters, a dot, and anything (or nothing) following the dot.
Wildcard | Matches |
---|
* |
zero or more characters
|
? |
exactly one character
|
[abxy] |
exactly one character from the list (a, b, x or y)
|
[a-e] |
exactly one character in the given range (a, b, c, d or e)
|
[!abxy] |
any character that is not listed
|
[!a-e] |
any character that is not in the given range
|
{beef,fish,tofu} |
exactly one entire word from the list in curly brackets (beef, fish or tofu)
|
~
: shortcut to your home directory
You can reference your home directory in your commands and programs with the character tilde ~
shortcut. If your home directory is
/sscc/home/a/abc123
then instead of writing out the full path to the file
/sscc/home/a/abc123/data/input.dat
you can just write
~/data/input.dat
Further Information
The software installed upon our HPC runs under the Linux/Unix operating system.
Ther is an excellent beginners' guide to the basic commands , which you may need, written by M. Stonebank at the University of Surrey. It is worth putting in some effort here as your research productivity will be really enhanced by learning Linux.
Tutorials are shared under a .