Linux Seventh Day: (August 05) Text Processing tool

Linux Seventh Day: (August 05) Text Processing tool

Head-n Specify the first n rows of the right of shipment
TAIL-N Specifies to get the following n rows
Tail-f displaying new additions to files

Cut-d indicates delimiter, default tab
Cut-f the first few fields
Cut-c cut by character

PASTE-D Specifies the delimiter file1 file2
Paste-s all rows are composited on a single line display

Wc-l count rows
Wc-w statistics of words
Wc-c Count bytes
Wc-m Statistic character Count

Sort-r Reverse Sort
Sort-n Sort by number
Sort-f ignoring case
Sort-u Delete duplicate rows
Sort-t c as the field delimiter
Sort-k X

Uniq-c statistics per row repeat occurrences
uniq-d Statistics for Duplicate rows
Uniq-u statistics non-repeating rows

PASTE-D Specifies the delimiter file1 file2
Paste-s all rows are composited on a single line display

diff file1 file2 Comparison two file differences
Diff-u file1 file2 > File3.patch
Patch-b file1 file2 Automatic backup of changed files

Grep:global search REgular expression and Print out of the line
grep "$USER"/etc/passwd
grep ' $USER '/etc/passwd
grep ' WhoAmI '/etc/passwd
grep--color=auot to match the text coloring display
Grep-v show rows that cannot be matched
Grep-i ignoring case
Grep-n Display Line numbers
Grep-c count rows
Grep-o only matching strings are displayed
Grep-q silent, no output information
Grep-a n after n rows
Grep-b n Top N rows
n rows before and after Grep-c N
GREP-E comm1-e COMM2 Multiple or relationships
Grep-w Match Whole Word
Grep-e Use ere

REGEXP Basic Regular Expression BRE
REGEXP extended Regular Expression ERE, grep-e, Egrep

Character matching
. Match any single character
[] matches any single character within the specified range
[^] matches any single character outside the specified range
Metacharacters
[:d igit:] All numbers
[: Lower:] All lowercase letters
[: Upper:] All uppercase letters
[: Alpha:] All letters
[: Alnum:] All alphanumeric
[:p UNCT:] All punctuation
[: Space:] Space and Tab

Number of Matches
* matches the preceding character any number of times, including 0 times
. * Any character of any length
\? Matches the preceding character 0 or 1 times
\+ matches the preceding character at least 1 times
\{n\} matches the preceding character n times
\{m,n\} matches the preceding character at least m times, up to N times
\{,n\} matches the preceding character up to n times
\{n,\} matches the preceding character at least n times

Position anchoring
^ Beginning anchor, user mode leftmost
& End anchors for the right side of the pattern
^ $ for pattern matching whole line
^& Empty Line
^[[:space:]]*$ Blank Line
\< or \b The first anchor for the left side of the word pattern
\> or \b Ending anchor for the right side of the word pattern
\< \> Match Whole word

Group
\( \)

Egrep and extending to regular expressions

Character matching
Egrep = Grep-e
. Any single character
[] Specify the range of characters
[^] characters not in the specified range

Number of Matches
* matches the preceding character any number of times
? Matches the preceding character 0 or 1 times
{m} matches M-Times
{m,n} at least m times, up to N times

Extending regular Expressions

Position anchoring
^ Beginning of the line
$ End of line
\< \b First language
\> \b End of the language

Group
()
\1 \2 back to reference

C|cat C or Cat
(C|C) at cat or cat

Linux Seventh Day: (August 05) Text Processing tool