Several ways to replace a string with Linux

1. Basic replacement
: s/str1/str2/replaces the current line the first str1 is str2
: S/str1/str2/g replaces the current line with all str1 as str2
: N, $s/str1/str2/replaces the first str1 of each row in the beginning of the nth row to the last row is str2
: N, $s/str1/str2/g replace the nth line to the last row, and all str1 are str2 in each row
(n is a number, if N is., representing the beginning of the current line to the last row)
:%s/str1/str2/(equivalent to: g/str1/s//str2/) replaces the first str1 of each line as str2
:%s/str1/str2/g (equivalent to: g/str1/s//str2/g) replaces all str1 in each row as str2
2. You can use # as a delimiter, at which time the middle appears/does not act as a delimiter
: s#str1/#str2/# Replace the current row the first str1/is str2/
:%s+/str11/str12/+/str21/str22+ (use + to replace/):/str11/str12/Replace with/str21/str22/
3. Delete ^m in file
Problem description: For line breaks, Windows uses a carriage return (0a0d) to indicate that Linux is a carriage return (0A). That way, when you copy a file on a window to UNIX, there's always a ^m, write a shell or C program that uses a newline character (0D) that filters Windows files under UNIX. There are two ways to do this:
(1) using the command: Cat Oldfilename | tr-d "^v^m" > NewFileName
(2) Use command: Sed-e "s/^v^m//" Oldfilename > NewFileName
It is important to note that in 1, 22 methods, ^v and ^m refer to Ctrl + V and ctrl+m. You have to do the input manually, not paste it.
Processing in VIM: First use VIM to open the file, then press ESC, then enter the command:
:%s/^v^m//
:%s/^m$//g
If the above method is useless, the correct solution is:
(1) tr-d "\ r" < Old_file_name > New_file_name or cat oldfilename | Tr-d "\ r" > New_file_name
(2) tr-d "\015" < Old_file_name > New_file_name or cat oldfilename | tr-d "\015" > New_file_name
Strings A>b
4. Other tricks
Use the: s command to implement a string substitution. Specific uses include:
: s/str1/str2/replaces the first occurrence of a string in a line with a string str2 str1
: S/str1/str2/g replaces all occurrences of strings in a line with a string str2 str1
:., $ s/str1/str2/g Replace all occurrences of the current line to the end of the string with the string str2 str1
: 1,$ s/str1/str2/g replaces all occurrences of strings in the body with a string str2 str1
: g/str1/s//str2/g function Ibid.
As you can see from the Replace command above, G is placed at the end of the command to replace each occurrence of the search string, without G, to replace only the first occurrence of the search string, and g at the beginning of the command to replace all rows in the body that contain the search string.
(2) SED command replacement string
The basic syntax for sed substitution is:
The code is as follows:

Sed
' s/original string/replace string/'
Single quotes inside, s for substitution, three slash in the middle is a replacement style, special characters need to be escaped with a backslash "\", but the single quote "'" is no way to escape with a backslash "\", this time as long as the single quotation mark in the command is changed to double quotation marks on the line, for example:

The code is as follows:

Sed "s/original string contains '/substitution string contains '/'
The character to be processed contains single quotation marks
The three slash delimiter in the command can be replaced by a different symbol, which is more convenient to replace with more slashes, just follow the s definition, such as the question mark "?":

The code is as follows:

Sed ' s? original string? Replace String? '
A custom delimiter is a question mark
You can replace each matched keyword with g at the end, or replace only the first of each line, for example:
The code is as follows:

Sed ' s/original string/replace string/'
Replace all matching keywords
Up ARROW "^" means the beginning of the line, the dollar "$" symbol if the end of the lines in quotation marks, but in the introduction of the last row (the final line), here committed two, searched for half a day which symbol represents the first line, half a day just remembered, the first line is the number "1″ ah." Then adding a string at :

The code is as follows:

Sed ' s/^/added head &/g '//Added at all beginning of line
Sed
' s/$/& added tail/g '//added at the end of all lines
Sed ' 2s/original string/replacement string/g '//Replace line 2nd
Sed
' $s/original string/replace string/g '//replace last line
Sed ' 2,5s/original string/replacement string/g '//replace 2 to 5 lines
Sed
' 2, $s/original string/replace string/g '//replace 2 to last line
A replacement style can be executed in more than one command, with a semicolon ";" Separation, for example:

The code is as follows:

Sed ' s/^/added header &/g;s/$/& added tail/g '
Execute two substitution rules at a time
The output processed by SED is output directly to the screen, to be saved can redirect the output, or replace it with the parameter "I" directly in the file:

The code is as follows:

Sed-i ' s/original string/replacement string/g ' filename
Replace all occurrences in a file

Several ways to replace a string with Linux