"Go" Linux in the grep command detailed __linux

A detailed explanation of GREP commands in Linuxgrep commands are very useful in Linux, and pipelines (|) Used in conjunction, very powerful for searching text files. If you want to find a string in several text files, you can use the ' grep ' command. ' grep ' searches the text for the specified string.
Suppose you are searching for a file with a string ' magic ' in the '/usr/src/linux/documentation ' directory:

$ grep magic/usr/src/linux/documentation/*
sysrq.txt:* How do I enable the Magic SysRq key?
sysrq.txt:* I Use the Magic sysrq key?

Where the file ' Sysrp.txt ' contains the string, the SYSRQ function is discussed.

By default, ' grep ' searches only the current directory. If there are many subdirectories under this directory, ' grep ' will be listed in the following form:

Grep:sound:Is a Directory

This may make the output of ' grep ' difficult to read. Here are two ways to solve this problem:

explicitly require searching subdirectories: Grep-r
or ignores subdirectories: grep-d Skip
Of course, if you anticipate a lot of output, you can go through the pipe and transfer it to ' less ' for reading:

$ grep magic/usr/src/linux/documentation/* | Less

This way, you can read it more easily.

It is important to note that you must provide a file filtering method (*) for all files to be searched. If you forget, ' grep ' will wait until the program is interrupted. If you encounter such a situation, press <ctrl c>, and then try again.

Here are some interesting command line arguments:

grep-i pattern Files: case-insensitive search. The default case is case-sensitive,
Grep-l pattern Files: Only the matching file names are listed,
Grep-l pattern Files: Lists mismatched file names,
Grep-w pattern files: matches only the entire word, not part of the string (such as matching ' magic ', not ' magical '),
Grep-c number pattern files: matching contexts show [number] rows,
grep pattern1 | PATTERN2 files: Displays rows that match pattern1 or pattern2.
grep pattern1 Files | grep pattern2: Displays rows that match both PATTERN1 and pattern2.
Here are some special symbols for searching:

/< and/> Each mark the beginning and the end of the word.
For example:
grep man * will match ' Batman ', ' manic ', ' man ' and so on,
grep '/<man ' * matches ' manic ' and ' man ', but not ' Batman ',
grep '/<man/> ' matches only ' man ', not ' Batman ' or ' manic ' and other strings.
' ^ ': refers to the matching string at the beginning of the line,
' $ ': refers to a matching string at the end of the line,
If you are not accustomed to command-line arguments, try the ' grep ' of the graphical interface, such as Rexgrep. The software provides syntax such as and, or, not, and beautiful button:-). If you just need a clearer output, try Fungrep.