cut:
It divides a string or output.
syntax:
cut [option] Filename
option:
-d specifies a delimiter
-f Displays a particular
-c Displays a character
Displays the third field of the text using space as a delimiter:
$cut -d " " -f3 file_example
Display third and fourth fields:
$cut f3,4 file_example
Displays first to firth characters:
$cut -c 1-5 file_example
WC:
It provides a word or line count.
Syntax:
wc [option] file
Option:
-l lines
-w words
-c characters
Display lines, words and characters
$wc example
$wc -l example
$wc -w example
Diff:
Display different lines between two files.
$diff file1 file2
cmp:
It compares two file character by character.
$cmp file1 file2
Note: If file are same it doesn’t return any output otherwise it displays line number and character position.
tr:
It translate character by character.
$tr "a e i o u" "A E I O U" <sample
$tr "a-z" "A-Z"<sample
$tr -s " "<sample
$tr -d "a e i o u" <sample
$tr "," "\t" <sample
aspellcheck:
To check the spelling mistakes but not grammatical mistake
$aspellcheck sample
$aspellcheck test
Head:
Display top 10 lines of the file
$head sample
Display top 5 line
$head -5 sample
Tail:
Display last 10 lines of the file.
$tail sample
Display last 5 lines
$tail -5 sample
File is open continuously
$tail -f sample
Piping( | ):
Combine the two or more commands in to a single line.
Here the first command output it taken as the next commandinput
$ls -l| wc -l
$cat example|cut -d " " -f3 file_example
$cat example |head -20
&&:
Combine commands
$echo "This is text file" >file_example && cut -f3 example
To verify
$cat file_example
$echo "My original text" >> file_example && cat file_example
More:
To see the contents of a file in the form of page wise
$more example
Less:
To display file contents in page wise. But we can go to all directions
$less example
Options:
f -> Forward direction
d -> Backward direction
vi -> vi editor mode
q -> To quit
Tee:
It is used to write the data into the files as well as on the screen
$cat sample|tee file1 file2 file3
To verify
$cat file1
$cat file2
Sort:
Sort the output of a command or file.
Syntax:
sort [options] FILE
Options:
-r -> Sorts in reverse order
-b -> Ignores leading blanks
-n -> compares according to numerical string value
Examples:
$sort example
Reverse Order
$sort -r example
Display Numeric
$sort -n example
Unique Lines
$sort -u
Ignores Case
$sort -f example
Uniq:
List all the unique lines in a file or command output
$uniq example
Display non duplicate lines
$uniq -u example
Display only duplicated lines
$uniq -d example
$uninq file_example> uniq_file && cat uniq_file
In above command to view uniq lines in the sample file, create a new file based on output and view the contents of this new file.
Sed (Stream Editor):
To search and replace strings or patterns in the given file.
Sed is a multi-purpose filter command.
Syntax:
sed "s/old string name/ new string name/g" <filename>
s -> substitution.
g -> Global occurrence in every line.
Example:
$sed "s/unix/linux/g" sample
Ignore case
$sed "s/unix/linux/gi" sample
$sed "s/unix/linux/" sample
$sed "s/^unix/linux/gi" sample
Delete a a word from a file
$sed "s/unix//gi" sample