UNIX COMMANDS - 1

File Handling Utilities

mkdir

NAME
mkdir - make directories

SYNOPSIS
mkdir [OPTION] DIRECTORY...

DESCRIPTION
Create the DIRECTORY(ies), if they do not already exist.

-Z, --context=CONTEXT (SELinux) set security context to CONTEXT

-m, --mode=MODE
set file mode (as in chmod), not a=rwx - umask

-p, --parents
no error if existing, make parent directories as needed

-v, --verbose
print a message for each created directory

2. rmdir

NAME
rmdir - remove empty directories

SYNOPSIS
rmdir [OPTION]... DIRECTORY...

DESCRIPTION
Remove the DIRECTORY(ies), if they are empty.

-p, --parents
Remove DIRECTORY and its ancestors. E.g., ‘rmdir -p a/b/c’ is similar to ‘rmdir a/b/c a/b a’.

-v, --verbose
output a diagnostic for every directory processed

3. cd

NAME
cd - change the current directory
SYNOPSIS
cd [-L|-P] [dir]

DESCRIPTION
Changes the current directory.

4. ls

NAME
ls - list directory contents

SYNOPSIS
ls [OPTION]... [FILE]...

DESCRIPTION
List information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuvSUX nor --sort.

-a, --all
do not ignore entries starting with .
-r, --reverse
reverse order while sorting
-R, --recursive
list subdirectories recursively
-l use a long listing format

5. touch

NAME
touch - change file timestamps

SYNOPSIS
touch [OPTION]... FILE...

DESCRIPTION
Update the access and modification times of each FILE to the current time.

-a change only the access time
-c, --no-create
do not create any files
-d, --date=STRING
parse STRING and use it instead of current time
-f (ignored)

6. pwd

NAME
pwd - print name of current/working directory

SYNOPSIS
pwd [OPTION]

DESCRIPTION
Print the full filename of the current working directory.




7. cp

NAME
cp - copy files and directories

SYNOPSIS
cp [OPTION]... [-T] SOURCE DEST
cp [OPTION]... SOURCE... DIRECTORY
cp [OPTION]... -t DIRECTORY SOURCE...

DESCRIPTION
Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.

-i, --interactive
prompt before overwrite
-H follow command-line symbolic links
-l, --link
link files instead of copying

8. mv

NAME
mv - move (rename) files

SYNOPSIS
mv [OPTION]... [-T] SOURCE DEST
mv [OPTION]... SOURCE... DIRECTORY
mv [OPTION]... -t DIRECTORY SOURCE...

DESCRIPTION
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.

-f, --force
do not prompt before overwriting

-i, --interactive
prompt before overwrite

-v, --verbose
explain what is being done

9. ln

NAME
ln - make links between files
SYNOPSIS
ln [OPTION]... [-T] TARGET LINK_NAME (1st form)
ln [OPTION]... TARGET (2nd form)
ln [OPTION]... TARGET... DIRECTORY (3rd form)
ln [OPTION]... -t DIRECTORY TARGET... (4th form)
DESCRIPTION
In the 1st form, create a link to TARGET with the name LINK_NAME. In the 2nd form, create a link to TARGET in the current directory.In the 3rd and 4th forms, create links to each TARGET in DIRECTORY.

-i, --interactive
prompt whether to remove destinations
-s, --symbolic
make symbolic links instead of hard links

10. unlink

NAME
unlink - call the unlink function to remove the specified file

SYNOPSIS
unlink FILE
unlink OPTION

DESCRIPTION
Call the unlink function to remove the specified FILE.

11. cat

NAME
cat - concatenate files and print on the standard output

SYNOPSIS
cat [OPTION] [FILE]...

DESCRIPTION
Concatenate FILE(s), or standard input, to standard output.

-A, --show-all
equivalent to -vET
-n, --number
number all output lines
-s, --squeeze-blank
never more than one single blank line

12. more

NAME
more - file perusal filter for crt viewing
SYNOPSIS
more [-dlfpcsu] [-num] [+/ pattern] [+ linenum] [file ...]

DESCRIPTION
More is a filter for paging through text one screenful at a time.

-p Do not scroll. Instead, clear the whole screen and then display the text.
-c Do not scroll. Instead, paint each screen from the top, clearing the remainder of each line as it is displayed.
-u Suppress underlining.

Disk Utilities

1. du

NAME
du - estimate file space usage

SYNOPSIS
du [OPTION]... [FILE]...
du [OPTION]... --files0-from=F

DESCRIPTION
Summarize disk usage of each FILE, recursively for directories.

-a, --all
write counts for all files, not just directories
-b, --bytes
equivalent to ‘--apparent-size --block-size=1’
-c, --total
produce a grand total

2. df

NAME
df - report file system disk space usage

SYNOPSIS
df [OPTION]... [FILE]...

DESCRIPTION
df displays the amount of disk space available on the file system containing each
file name argument. If no file name is given, the space available on all currently mounted file systems is shown.

-a, --all
include dummy file systems

3. ulimit

NAME
ulimit - user limit

SYNOPSIS
ulimit [-SHacdefilmnpqrstuvx [limit]]

DESCRIPTION
Provides control over the resources available to the shell and to processes started by it, on systems that allow such control.


4. mount

NAME
mount - mount a file system

SYNOPSIS

mount [-lhV]
mount -a [-fFnrsvw] [-t vfstype] [-O optlist]
mount [-fnrsvw] [-o options [,...]] device | dir
mount [-fnrsvw] [-t vfstype] [-o options] device dir

DESCRIPTION

All files accessible in a Unix system are arranged in one big tree, the file hierarchy, rooted at /. These files can be spread out
over several devices. The mount command serves to attach the file system found on some device to the big file tree.

-V Output version.

-h Print a help message.

-v Verbose mode.

5. umount

NAME
umount - unmount file systems

SYNOPSIS
umount [-hV]
umount -a [-dflnrv] [-t vfstype] [-O options]
umount [-dflnrv] dir | device [...]

DESCRIPTION
The umount command detaches the file system(s) mentioned from the file hierarchy.

-V Print version and exit.
-h Print help message and exit.
-v Verbose mode.