escaping

问题 I want to execute powershell command and put it in batch variable The command: for /f "delims=" %%i in ('powershell ^(Get-ChildItem ""\dir\"" -Name | sort-object {\[regex\]::Replace^($_,^'\d+^',{$args\[0\].Value.PadLeft^(20^)}^)} | select -last 1^) ') do set output=%%i It can't be executed due special character. In addition, I can't pause the window so it closes before I can see what is the problem. I think the problem is with the pipe "|", because the following command does work(the part

问题 I have query to remove double space and convert it to single space. UPDATE tablename SET name=trim(regexp_replace(name,'\s\s+',' ', 'g')); It gives error: WARNING: nonstandard use of escape in a string literal HINT: Use the escape string syntax for escapes, e.g., E'\r\n'. 回答1: You are running an old version of Postgres with the setting escape_string_warning = on (default) and standard_conforming_strings = off ( outdated! , default is on since Postgres 9.1). The manual: escape_string_warning (

问题 Can anyone tell me what is happening here? <?php // true var_dump('\\ ' === '\ '); // false var_dump('\\\\ ' === '\\ '); // true var_dump('\\\\ ' === '\\\ '); 回答1: \ inside a string literal introduces several types of escape sequences, \\ is the escape sequence for a literal "\". But, \ s that don't resolve to an escape sequence are also taken as literal "\". Therefor, '\\ ' stands for the string "\ ", '\\\\ ' stands for the string "\\ ", just as '\\\ ' . Try: echo '\\\\ '; -> \\ See http:/

问题 Can anyone tell me what is happening here? <?php // true var_dump('\\ ' === '\ '); // false var_dump('\\\\ ' === '\\ '); // true var_dump('\\\\ ' === '\\\ '); 回答1: \ inside a string literal introduces several types of escape sequences, \\ is the escape sequence for a literal "\". But, \ s that don't resolve to an escape sequence are also taken as literal "\". Therefor, '\\ ' stands for the string "\ ", '\\\\ ' stands for the string "\\ ", just as '\\\ ' . Try: echo '\\\\ '; -> \\ See http:/

问题 I am allowing the user to choose any username he wants and it can be anything at all such as AC♀¿!$"Man'@ Now i need to create a directory for him. What function i use to escape the text so i dont a FS problem/exception? 回答1: Use Path.GetInvalidFileNameChars or Path.GetInvalidPathChars to check for characters to remove. http://msdn.microsoft.com/en-us/library/system.io.path.getinvalidfilenamechars.aspx 回答2: Whether you replace invalid characters or remove them, there's always going to be the

问题 My knowledge of commandline bash is missing on a particular area: I constantly forget how to properly escape characters. Today I wanted to echo this string into a file: #!/bin/env bash python -m SimpleHTTPServer However, this fails: echo "#!/bin/env bash\npython -m SimpleHTTPServer" > server.sh && chmod +x server.sh -bash: !/bin/env: event not found That's right: Remember to escape ! or bash will think it's a special bash event command. But I can't get the escaping right! \! yields \! in the

问题 I found this website with escape codes and I'm just wondering if someone has done this already so I don't have to spend couple of hours building this logic: StringBuffer sb = new StringBuffer(); int n = s.length(); for (int i = 0; i < n; i++) { char c = s.charAt(i); switch (c) { case '\u25CF': sb.append("●"); break; case '\u25BA': sb.append("►"); break; /* ... the rest of the hex chars literals to HTML entities */ default: sb.append(c); break; } } 回答1: These "codes" is a mere decimal

问题 I found this website with escape codes and I'm just wondering if someone has done this already so I don't have to spend couple of hours building this logic: StringBuffer sb = new StringBuffer(); int n = s.length(); for (int i = 0; i < n; i++) { char c = s.charAt(i); switch (c) { case '\u25CF': sb.append("●"); break; case '\u25BA': sb.append("►"); break; /* ... the rest of the hex chars literals to HTML entities */ default: sb.append(c); break; } } 回答1: These "codes" is a mere decimal

问题 I need a function like string ToLiteral(string input) from this post. Such that char *literal = to_literal("asdf\r\n"); Would yield literal ==> "asdf\\r\\n" . I've googled around, but not been able to find anything (guess that I've must be using the wrong terms). However, I assume that a library with this functionality must be out there somewhere... Thank you for the interresting answers. Googling "c string escape function" by the way seems to be the key to obtaining even more examples and

问题 Suppose that I have a document like this, and I want to search for all occurences of the URL: Vim resources: [http://example.com/search?q=vim][q] ... [q]: http://example.com/search?q=vim I don't want to type it out in full, so I'll place my cursor on the first URL, and run "uyi[ to yank it into the 'u' register. Now to search for it, I'd like to just paste the contents of that register into the search field by running: /\V<c-r>u<CR> This results in Vim searching for the string 'http:' -