4.4. Escape Special Characters in Here String To escape special characters like $, , and `, we can enclose the string with the single quote instead of the double quote: cat<<<'Display special characters: $ ` \' If we enclose the here string with a single quote, variable expansion such ...
Enclosing characters in double quotes (‘"’) preserves the literal value of all characters within the quotes, with the exception of ‘$’, ‘`’, ‘\’, and, when history expansion is enabled, ‘!’. The characters ‘$’ and ‘`’ retain their special meaning within double quotes (see...
但稍微有难度的是shell里面的那些个符号，各种特殊的符号在我们编写Shell脚本的时候如果能够用的好，往往...
/* Quote special characters in STRING using backslashes. Return a new string. NOTE: if the string is to be further expanded, we need a way to protect the CTLESC and CTLNUL characters. As I write this, the current callers will never cause the string to be expanded without going through ...
http://download.oracle.com/javase/tutorial/java/data/characters.html In Bash 字符串的用途 在Bash中无处不是字符串,它可以 (1)作为命令; (2)作为命令行参数; (3)作为变量的值; (4)作为重定向的文件名称; (5)作为输入字符串(here string, here document); ...
In this example we declare simple bash variable and print it on the screen ( stdout ) with echo command. #!/bin/bash STRING="HELLO WORLD!!!" echo $STRING 1. 2. 3. Your backup script and variables: #!/bin/bash OF=myhome_directory_$(date +%Y%m%d).tar.gz ...
If the shell option nocasematch is enabled, the match is performed without regard to the case of alphabetic characters. Any part of the pattern may be quoted to force it to be matched as a string. Substrings matched by parenthesized subexpressions in the regular expression are saved in the ...
3. Escape Special Characters:Minimize the use of special characters in regex patterns to avoid unintended matches or errors. i.e. Don’t forget to put a backslash (\) before special characters in your regex. This prevents them from causing unexpected matches or errors. ...
enabled, the match is performed without regard to the case of alphabetic characters. Any part of the pattern may be quoted to force the quoted portion to be matched as a string. Bracket expressions in regular expressions must be treated carefully, since normal quoting ...
will produce the same results as if you surrounded the string with single quotes. To use a literal backslash, just surround it with quotes ('\') or, even better, backslash-escape it (\\). Here is a more practical example of quoting special characters. A few UNIX commands take arguments...