Application of shell script learning advanced and regular expression

Sort order:

-F:     ignore character case-N:    Compare numeric Size-T:    specify delimiter    -K: Specify to compare field ordinals after delimited-u:    duplicate rows, only once

　

Sort by the second row of values:

$ sort-k2n SORT.TXTCCC 8aaa 11yyy 12eee 22

Duplicate rows are displayed once: Sort-u sort.txt

Uniq handles duplicate rows , using the sort together:

WC command:

Line | Characters | Word $ WC sort.txt 6 sort.txt$ wc-l sort.txt 6 sort.txt$ wc-c sort.txt (sort.txt$ wc-w sort.txt) sort.txt

　　

Find command:

Find by name $ find./-name "*.sh" Find the normal file under the current level directory $ find/-maxdepth 1-type F Find the size between 1M and 5M find to-size +1m-size-5m look for the log directory 10 days Previously created file $ find ~/log-ctime +10 Find the log directory created within 5 days of the file $ find ~/log-ctime-5

　　

The LS command cannot read a pipe or standard input and can use EXEC instead:

Find ~/log-ctime +10-exec Ls-la {} \;

　　

Using the OK option is more secure and requires confirmation:

Find ~/log-ctime +10-ok rm-f {} \;

　　

Of course, you can also use Xargs to parse the output of the previous command into small chunks:

Find./-maxdepth 1-type-f | Xargs ls-l

　　

The grep command can be used to find content:

-R Recursive Sub-directory

-I ignores case

-V Exclusion

The regular expression shows:

Character class:

Quantity limit:

Position qualifier:

Special characters:

You can use the EGREP command to support an extended regular expression:

Example 1: Match out all IP addresses XXX.XXX.XXX.XXX

Egrep ' ^[0-9]{1,3}\. [0-9] {1,3}\. [0-9] {1,3}\. [0-9] {1,3}$ ' All.txt

Example 2: Matching mailbox [email protected]| CN

Egrep ' [0-9a-za-z][email protected][0-9a-za-z]+\. (COM|CN) $ ' all.txt

Note: There is currently a basic regular and extended regular, the foundation is not supported? +  { }  | （）.

If you want to support, you need to escape the character, write to write the extended regular, write the basic regular.

grep ' [0-9a-za-z]\[email protected][0-9a-za-z]\+\.\ (com|cn\) $ ' all.txt or grep-e ' [0-9a-za-z][email protected][ 0-9a-za-z]+\. (COM|CN) $ ' all.txt

Finally, the matching IP address is optimized once:

　　

sed tool , Stream Editor, and VI of the same origin, processing files, modify the text!

Common usage:

SED option ' script ' file1 file2 ...               ' Sed parameters    ' script (/pattern/action) ' Pending file sed option-f scriptfile file1 file2 ...           Sed parameter –f ' script file ' pending file

Parameter description:

A,    append             append i,    insert             insert D,    delete             delete s,    substitution     Replace

Example: inserting XXXX in the second line

Sed ' 2ixxxx ' cash.sh

-I is a direct modification of the source file and requires careful use

Delete 4–6 line:

Sed ' 4,6d ' cash.sh

Replace read for write:

Sed ' s/read/write ' cash.sh

Sed Common directives:

/pattern/p prints lines that match the pattern/pattern/d Delete rows matching the pattern/pattern/s/pattern1/pattern2/find rows that match the pattern, Replace the first string that matches pattern1 in the row with pattern2/pattern/s/pattern1/pattern2/g to find the line that matches the pattern, and replace all strings that match pattern1 in the row with pattern2

For example, match echo and print the line:

Sed '/echo/p ' cash.sh

　　

Multiple lines are displayed, and if you need to not enter the source file content, you can use:

Sed '/echo/p ' cash.sh-n

　　

Use of address symbols:

Sed ' s/23/-&-/' cash.sh

　　

\1 \2 represents the corresponding first cell and second cell

-R can be used to extend the regular

Remove HTML Tags:

Sed-r ' s/<[(/|0-9a-za-z)]+>//g ' hello.html or sed-r ' s/<[^<>]+>//g ' hello.html

　　

　

　　

Application of shell script learning advanced and regular expression