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5.02 Files/Directories Utilities
ls - list
directory contents (shows listing, index that point to actual inodes,
files)
Options:
-1
list (one)
-C columns
-F flags (File or directory)
-R Recursive (travels directory tree from the top down, and shows
as well all files)
-S size
-X extension
-a all
-d directory names
-k
kilobytes (needs to be combined with the -s option)
-l long (provides a long format, which includes file details
with the -t, list in revere time order)
-m commas
-r reverse
-s size
-t time
-x horizontally
dirs -
displays
the stack
Options:
-c
clears
-l long
-p preface
-v verbose
pushd - pushes
a directory on the stack
dir
directory name
+N number
-N nu
Example:
|
[bash]$
pushd mnt/floppy/bikes
[bash]$
pushd mnt/floppy/cars |
popd - removes
directories from the directory stack
+N number
-N number
cd - changes
to another working directory (change directories)
cd alone moves you to
the home directory
Dot(.) indicated current
directory number
Double Dot(..) is a parent
directory
pwd - print(display)
working directory
mkdir - creates
a directory
Options:
-p parent #creates parent
and child directories
-v verbose #display steps
being made
rmdir - deletes
directory
Options:
-p parent
-v verbal
rm - deletes
a files or directories
Options:
-d directory
-f force
-I interactive
-r, R recursively
-v verbose
mv - changes
the name of a file
Options:
-f force
-u update (move only
when source file is newer than the destination file, or when destination
file is missing)
-i interactive
-v verbose
file - test
the contents of a file
Options:
-b brief mode
-i mime (Multi Purpose
Internet Extension)
-s special files
-v version of file and
location of magic file
-z tries to look inside
compressed files.
-
endian:refers to
the ordering of bytes in a multi-byte number
-
little-endian: is
an order in which the little end (least signifant value in the sequence)
is stored first
-
big-endian: is in
contrast to little-endian, in which the big end (most significant
value in the sequence) is stored first
touch
- changes file timestamps
cp - copies
a file
Options:
-b backup (creates a
backup file if overwritten with a ~ sign, and will preserve the attributes
of the orginal file, such as permissions and the date)
-f force
-i interactive
-p preserve the attributes
of the original file, such as permissions and the date)
-r, R recursively
-v verbose
Example:
|
[bash]$
cp *.foo1 *.foo2 foo.filedirectory |
cmp - compares
the contents of two files from each other. Reports the first different
character found, and the line number
cat - display
a text file # (does not allow to scroll, but piped ( |
) with more or less you can)
-A show all (will show
even non printing characters)
-b numbers non blank
output lines
-e equivalent to –vE
- E display a $ at the
end of each line
-n numbers all output
lines
-t equivalent to –vT
-T displays tab characters
as ˆI
-v Uses the ˆ and
M to show non printing characters except for line feeds and tabs
Example: How
to create a file by redirection
using a cat command
|
[bash]$cat
foo*.* > foo.file #(Displayed
text redirects to a foo.file) |
Example: How
to create simple script using a cat
commands and redirection
|
[bash]$
cat > commands
# (creates script on to go)
dd
# (delete a line)
G #
(go to the bottom)
p #
(paste the line)
:wq #
(write the file to a disk and quit)
vim foo.file
< commands # (execute script on the foo.file) |
Example:
Using a cat - to
determine which version of the OS is installed
Example: Using
cat - to determine
what file systems are mounted and where they are mounted
Example:
username:password:uid:gid:comments:homedir:shell
Example: checks
the fstab
file for the actual name of your floppy drive, and the whereis
command verified the location of fdformat
and mkfs.
|
[bash]$cat/etc/fstab;
whereis fdformat mkfs |
more - file
perusal filter for CRT viewing. Its is a filter for paging through text
one screen at the time. This version is especially primitive. The command
Less provides more emulation and extensive enhancements.
less - is
a program similar to more, but which allows backward movement.
With large files starts up faster that text editors.
Example: How
to use more and
less commands
|
[bash]$ more
*.foo
#(or)
[bash]$
less *.foo |
touch
- changes file time stamp
-a changes access time
-c do not create any files ( this prevent touch from creating
a file if already exists.)
-m only changes modification time
ln - creates
a hard link
ln –s - creates
a symbolic link to an existing file
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