One linux command per day: diff

The diff command is used to compare the content of a file line by line and list its differences. Diff -- help can be used to view command parameters. Difffile1file2 compares the content in file1 and file2. the displayed results are as follows: 1c1, 3 & lt; hello --- & gt; world & gt; 123 & gt; 23-letter-old pair...
The diff command is used to compare the content of a file line by line and list its differences. Diff -- help can be used to view command parameters. Diff file1 file2 compares the content in file1 and file2. the format of the result is as follows: 1c1, 3 World> 123> 23 the corresponding file1 file before the letter, and the corresponding file2 file after the letter, the letter form is as follows: a (add), d (delete), c (Modify ). Number indicates the number of rows. Www.2cto.com <Followed by the content in file1,> Followed by the content in file2. --- It is a gorgeous split line. You can also use the standard input instead of the file, that is, do not write the file name, use-(minus sign) instead, then use the standard input, and use ctrl + D to end. The output content format is similar to the preceding one. You can also choose not to specify a file. if you use a directory, the files with the same file name are automatically compared. The following describes the available parameters:-I ignore case sensitivity. -B ignores multiple spaces. Multiple spaces are considered as one. -W ignores all spaces. -B ignores empty rows. -Q only shows whether there are any differences. -The content of files y is displayed in two columns. Author: CrazyNemo