What are the methods for shell to read files by line?
This article mainly introduces "what are the methods for shell to read files by line". In daily operation, I believe that many people have doubts about the method of reading files by line in shell. The editor has consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "what is the method of reading files by line by shell?" Next, please follow the editor to study!
There are many methods, three of which are written below:
Write method 1:
The code is as follows:
#! / bin/bash
While read line
Do
Echo $line
Done < filename (file to be read)
Writing method 2:
The code is as follows:
#! / bin/bash
Cat filename (File to be read) | while read line
Do
Echo $line
Done
The third way of writing:
The code is as follows:
For line in `cat filename (file to be read) `
Do
Echo $line
Done
Description:
There is a difference between for line-by-line reading and while line-by-line reading, such as:
The code is as follows:
$cat file
1111
2222
3333 4444 555
$cat file | while read line; do echo $line; done
1111
2222
3333 4444 555
$for line in $(
