The String.format() method provides versatile formatting capabilities. This tutorial tries to present these capabilities in a accessible manner. The format string A format string can contain zero, one, or more format specifiers . The general form of a format specifier is: %[argument_index$] [flags] [width] [.precision]co... where things in square brackets are optional, and conversion is a character indicating the conversion to be applied to the corresponding variable value. The only required characters in the format specifier is the percent sign % and the conversion character. A simple example: public static void simpleFormat() { System.out... The Argument index The argument index is specified by a number, terminated by the dollar sign $ . The same argument may be repeated multiple times in a format string. Unindexed...

This is normally a syntax error just before some variable. Try some of these: Missing operator before a variable: <?php $a = 'ab'; echo('Missing conca... Missing semicolon at end of line: <?php echo('Missing semicolon at end of lin... Missing ( and ) in for loop: <?php foreach $a as $i { echo "$i\n"; ... Missing keyword before class variable: <?php class A { // should be var $a; ...

PHP global variables are defined outside of functions and classes. They are visible both in the current file and in any included/required files. Also, any global variables defined in required/included files are visible in the current file. But they are not visible in any functions or classes, unless specifically declared global . Test: Create file test.php : <?php ini_set('display_errors', 'stderr'); i... Create file test.inc : <?php echo '[', __FILE__, '] $a . $b = ', $... Run the PHP script in command line: php test.php 2>C:\tmp\stderr.out The result is: [C:\work\test.inc] $a . $b = ab [C:\work\test.p... stderr messages: PHP Notice: Undefined variable: b in C:\work\scra...

In PHP, a heredoc string starts with <<< followed immediately by an end tag and a new line, and ends by the end tag on its own line followed by a semi-colon. Example: <?php $v = "variable"; $s = <<<END_TAG ...

Check the __name__ variable to see if the Python module was invoked from the command line. The line prints when the Python script is called from the command line, but doesn't print when it is imported by another Python module with import MyModule . if __name__ == '__main__': print 'Invoked f...

The Unix shell passes these parameters to the shell script: Variable Meaning $* A single string representing all command line arguments separated by $IFS (internal field separator, usually a space) $@ A sequence of strings representing the command line arguments. $1,$2...$n $1 is the first argument, $2 is the second argument, and so on... $0 The name of the script itself. $# The number of arguments. Example shell script ( sharg.sh ): #!/bin/sh echo $# arguments passed to $0: $@ ... Output for ./sharg.sh "a b c d" : 1 arguments passed to ./sharg.sh: a b c d here ... Output for ./sharg.sh a "b c" d : 3 arguments passed to ./sharg.sh: a b c d here ...

If Command Extensions are enabled (which is enabled by default), then there are several dynamic environment variables that can be expanded but which don't show up in the list of variables displayed by SET . These variable values are computed dynamically each time the value of the variable is expanded (but see example below). If the user explicitly defines a variable with one of these names, then that definition will override the dynamic one described below: %CD% - expands to the current directory string. %DATE% - expands to current date using same format as DATE command. %TIME% - expands to current time using same format as TIME command. %RANDOM% - expands to a random decimal number between 0 and 32767. %ERRORLEVEL% - expands to the...

By the perldoc , use Module LIST; is exactly equivalent to: BEGIN { require Module; Module->import( LIST); } Because of the BEGIN block, use is executed immediately. Therefore, it is not suitable for lazy loading of modules at runtime. use does not work with a runtime variable: C:\>perl $cgi = "CGI"; require $cgi; prin... require works: C:\>perl $cgi = 'CGI'; require "${cgi}.pm"; ... Also, file extension is required if require is not passed a bareword: // this works require CGI; // so does th...

The log line was like this: 2011-01-19 15:16:34,842 INFO [STDOUT] (HDScanne... Note that INFO and timestamp were printed twice. Based on my configuration, I was expecting something like this: 2011-01-19 15:16:34,842 INFO [XmlWebApplicationC... i.e., the logger name should have been XmlWebApplicationContext , not STDOUT ! What was the problem? I found this error message in server.log : 2011-01-19 14:34:38,107 ERROR [STDERR] (main) lo... It turned out that org.apache.log4j.Appender was loaded by my web application class loader, whereas org.jboss.logging.appender.FileAppender was loaded by the JBoss bootstrap class loader. Removing the log4j jar from my web application archive fixed the problem (sine log4j is already available in JBoss). Why was the logger changed to STDOUT? JBoss detects that there's a problem with the log4j configuration and routes all...

This is the error: >>> import urllib2 >>> f = urllib2.urlopen('htt... Reason: SSL is not supported in Python installation. >>> import httplib >>> hasattr(httplib, 'HTTPS'... Solution: recompile Python with SSL on Steps: Download and install OpenSSL , if you don't have it already. Download Python source and rebuild Python (the usual steps of configure, make and make install). Python's configure script should be able to pick up your existing SSL libraries automatically and build a shared library _ssl.so. Some web sites suggest editing the file Modules/setup.dist , uncomment the lines starting with _ssl , and making changes to the SSL path. This would link the SSL library statically to Python. # Socket module helper for socket(2) #_socket s...