Oracle sqlplus command line tools does not support command line editing out-of-the-box. But on Linux there's a handy utility that enables command line editing with any command line tool: rlwrap - readline wrapper. Install rlwrap: $ sudo apt-get install rlwrap Create a keywords file .sql.dict (optional, but convenient): false null true access add as asc begin by chec... It would be nice to add the tables names also. Create an alias for sqlplus (put it in .bashrc ): alias sqlplus='rlwrap -f $HOME/.sql.dict sqlplus'

Unlike CVS, svn does not have a tag command, you create a new tag with copy : $ svn copy http://svn.example.com/repos/calc/trunk... The -r flag may be used to create a tag from an earlier revision: -r [--revision] ARG : ARG (some commands al...

Got this error while trying to build Android app: [apkbuilder] Creating AppInfo-debug-unaligned.ap... Solution: Delete the Android debug keystore: $ rm ~/.android/debug.keystore Build again: $ ant debug The new key is valid for 30 years (keystore password is 'android'): $ keytool -list -v -keystore ~/.android/debug.keys...

Linux services startup order in general: kernel runs /sbin/init /sbin/init reads /etc/inittab and runs script defined by this line: si::sysinit:/etc/init.d/rcS switches to runlevel defined by id:3:initdefault: which causes /etc/init.d/rc to be called with the current run level. /etc/init.d/rc calls the scripts under the /etc/rc <current_run_level> .d directory (symbolic links to actual scripts under /etc/init.d/ ) in this order: The KILL scripts first (scripts with name starting with K, i.e., rc?.d/Knn name ): "script_name stop" then, the START scripts (scripts with name starting with S, i.e., rc?.d/Snn name ): "script_name start" Within each group (KILL or START), run scripts from lower priority number (i.e., the nn in the symlink name) to higher priority number. The Upstart init daemon does not use /etc/inittab . Instead, it...

Here, = prints line number followed by new line, N appends the next line of input into the pattern space . Print line number at beginning of line, followed by a space: sed = test.txt | sed 'N;s/\n/ /' Print line number at beginning of line, followed by a tab: sed = test.txt | sed 'N;s/\n/\t/' Print line number right adjusted with 6 leading spaces: sed = test.txt | sed 'N; s/^/ /; s/\(.\{6,\}\...

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...

The PHP constant __FILE__ is the current file name, __LINE__ is the current line number. These can be helpful writing error logs. <?php // __LINE__ is the current line numbe... Outputs: Current file is C:\scrap\test2.php, current line n...

There are two variables you can use while writing command line applications with PHP - $argc and $argv : $argc is the number of arguments plus one (the name of the script running). $argv is an array containing the arguments, starting with the script name as number zero ( $argv[0] ). Example: #!/usr/bin/php <?php var_dump($argv); ?>

grep is a versatile command with many variations (grep, egrep, fgrep, then various implementations). It uses a regula expression (regex) pattern to filter input. But then there are basic and extended flavors of regex - leading to even more confusion. And, beware that there are lots of bad examples of regex in the wild... There are two critical questions to ask when you use grep: which grep implementation are you using? what is the flavor of the regex? Here are some examples for gnu grep v2.7: # Find all numbers (no decimal point), basic regex... Use the -o flag to show only the matching part instead of the whole matching line: grep -o -E '\b[0-9]{2}\b' The good thing about the gnu grep is that it...

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 ...