Search command grep under Linux

First, Introduction

grep(Global search Regular expression (RE) and print out of the line, full search of regular expressions and print out rows) is a powerful text search tool that uses regular expressions to search for text. and print out the matching lines.

Usually grep combines duct | To use, for example, to get results from the previous command through the pipeline | Pass to grep for filtering

Second, the option

-A Do not ignore binary data. -A < Displays the number of columns > displays the contents of the row, in addition to the row that conforms to the template style. -B appears outside the row that conforms to the template style and displays the contents before the line. -C calculates the number of columns that conform to the template style. -C< show columns > or-< Displays the number of columns > in addition to displaying the column that conforms to the template style, and displays the contents before the column. -D< action > You must use this parameter when you specify that you want to find a directory instead of a file, otherwise the grep command returns information and stops the action. -E< template style > Specify a string as the template style for finding the contents of a file. -E uses the template style as an extended normal notation, which means that extended regular expressions can be used. -F< template file > Specify a template file with the contents of one or more template styles so that grep finds the contents of the file that match the template criteria, formatted as a template style for each column. -F treats the template style as a list of fixed strings. -G uses the template style as a normal notation. -H does not indicate the file name that the column belongs to until it displays the column that conforms to the template style. -h indicates the file name of the column before displaying the column that conforms to the template style. The difference between the case of the-I-Hu character. -l lists file names that match the file contents to the specified template style. -l lists file names for file contents that do not conform to the specified template style. -N indicates the column number before displaying the column that conforms to the template style. -Q does not display any information. -R/R The effect of this parameter is the same as specifying the "-D recurse" parameter. -S does not display an error message. -V Reverse lookup. -W displays only the columns that match the whole word. -X displays only the columns that are eligible for all columns. -y This parameter effect is the same as "-I". -O outputs only the portion of the file that matches. 

Iii. common usage of GREP commands

Searching for a word in the file, the command returns a line of text containing "Match_pattern":

"Match_pattern" file_name

Find in multiple files:

grep "Match_pattern" File_1 file_2 file_3 ...

Output all rows except the- v option:

Grep-v "Match_pattern" file_name

Mark Match color --color=auto options:

grep "Match_pattern" file_name--color=auto

Use the regular expression- e option:

Grep-e "[1-9]+""[1-9]+"]

Output only the portion of the file that matches to the- o option:

Echo This was a test line. | Grep-o-E "[A-z]+\."] Line. Echo This was a test line. | Egrep-o "[A-z]+\.] Line.

The number of rows in the statistics file or text containing the matching string- c option:

Grep-c "Text" file_name

The output contains the number of rows that match the string- n option:

grep "text" "Text"- n#"text"-N file_1 file_2

The character or byte offset at which the plot style matches:

Echo  not Unix | Grep-b-O ' not ' 7: not
#一行中字符串的字符便宜是从该行的第一个字符开始计算, the starting value is 0. Option-b-o is always used in conjunction.

Search for multiple files and find matching text in which files:

Grep-l "text" File1 file2 file3 ...

Four, grep recursive search file

To recursively search for text in a multilevel directory:

grep "Text". -r-n#. Indicates the current directory.

Ignore character case in matching style:

Echo "Hello World" | Grep-i "Hello"Hello

Option- e brakes Multiple matching styles:

Echo This was a text line | Grep-e "is"-e "line" -oisline# You can also use the-f option to match multiple styles, writing out the characters that need to be matched line by row in the style file. Cat patfileaaabbbecho AAA bbb CCC DDD Eee | Grep-f Patfile-o

Include or exclude the specified file in the grep search results:

#只在目录中所有的. PHP and. html files recursively search for the character "main ()""main ()". -R--include *. {PHP,html}#"main ()". -R--exclude "README"# "main ()". -R--exclude-from FileList

grep with Xargswith a 0 -value byte suffix:

# Test files:echo "AAA" > file1echo "BBB" > file2echo "AAA" >  "AAA" file*-lz | xargs-0 RM#执行后会删除file1和file3, the grep output uses the-Z option to specify a 0-value byte as the Terminator file name, xargs-0 reads the input with a 0-value byte terminator separates the file name, and then deletes the matching file,- Z is usually used in conjunction with-L.

grep Silent output:

Grep-q "test" filename#不会输出任何信息, if the command runs successfully returns 0, a non-0 value is returned if it fails. Typically used for conditional testing.

Print a line before or after matching text:

#10 | grep "5"-A 35678#10 | grep "5"-B32345# 10 | grep "5"-C 32345678# If there are multiple matching results, "--" is used as the delimiter between each matching result:echo -E "A\NB\NC\NA\NB\NC" | grep a-a 1ab--ab

Above transfer from: Http://man.linuxde.net/grep

Search command grep (GO) under Linux