![]() However breaking out allows us to get to where we want to be. You actually can't put single quotes inside of a single-quoted string. In conclusion, the title of this post is a bit of a misnomer. Like so:īecause ' is not inside of single quotes the single-quote is properly escaped and the output is as we'd expect: this is a string' The first ' turns quoting on, the next turns it off. Double quotes are a simple state machine. Here are some important notes about using double quotes ' with cmd.exe. various command line utilities often makes it a challenge to discover the correct syntax needed for any given situation. To single quotes work you need to break out of the single quoted string then escape your single quote. The inconsistent escape and quote rules used by cmd.exe vs. This doesn't work because the escaped single-quotes ( ') are not expanded and are therefore treated literally. Here is a more practical example of quoting special characters. To use a literal backslash, just surround it with quotes ( '\') or, even better, backslash-escape it ( \\ ). will produce the same results as if you surrounded the string with single quotes. Escape characters all start with the backslash key ( \) combined with another character within a string to format the given string a certain way. Another way to format strings is to use an escape character. bin/bash: -c: line 2: syntax error: unexpected end of file For example: echo 2 \ 3 \> 5 is a valid inequality. With triple quotes, you can print strings on multiple lines to make text, especially lengthy text, easier to read. First you enclose Louis Theroux in single quotes for Bash and double quotes for ssh: 'Louis Theroux'. bin/bash: -c: line 1: unexpected EOF while looking for matching `'' This is because the unquoted string will be expanded and BASH will think that /'/g' bin/bash: line 1: p: No such file or directory If I want to use sed to match some text with a single quotes in it, I will run into trouble if I run: The characters and retain their spe cial meaning within double quotes. 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. However if you want to use single quotes within a single quoted string things don't work out as you might expect.įor example using the following simple PHP snippet: this is a string' A sin gle quote may not occur between single quotes, even when preceded by a backslash. Remember that if you want to use single backslash, you have to escape it: \\.Using single quotes in BASH ensures that the shell doesn't expand the contents of the quoted string and this is useful most of the time. That effectively means that \' becomes ', \" becomes " and so on. When enclosing string in $'string' all characters preceded by backslash are replaced according to ANSI C quoting. This effectively outputs three strings - 'test ', single quote and ' 123'. That means that the above example comes to Closing the string right before the single quote, then use escaped single quote, then open another single quoted string There are two approaches to achieve this. Is interpreted as the string test \, then 123 then opening new string. Double quotes escape most characters, except the double quote ' the backtick, the dollar sign, the backslash \, and the. ![]() A single quoted string of ''\' will represent exactly those characters. Single quotes escape every special character except the single quote itself. Unfortunately single-quoted string cannot contain single quote, or in other words the second quote encountered is interpreted as end of string. The difference between single quotes and double quotes is important. using tools that require special characters as arguments like sed There are several cases where one would want to have single quote in single-quoted string.
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