Tutorial by Examples: g

Let's assume that the field separator is : var='1:2:3:4: newline' arr=() while IFS= read -d : -r field || [ -n "$field" ]; do arr+=("$field") done <<< "$var" echo "${arr[4]}" Output: newline

Let's assume that the field separator is : while IFS= read -d : -r field || [ -n "$field" ];do echo "**$field**" done < <(ping google.com) Or with a pipe: ping google.com | while IFS= read -d : -r field || [ -n "$field" ];do echo "**$field**&q...

pat='[^0-9]+([0-9]+)' s='I am a string with some digits 1024' [[ $s =~ $pat ]] # $pat must be unquoted echo "${BASH_REMATCH[0]}" echo "${BASH_REMATCH[1]}" Output: I am a string with some digits 1024 1024 Instead of assigning the regex to a variable ($pat) we could als...

A simple example which provides the options: OptAlt. OptDetails-h--helpShow help-v--versionShow version info-dr path--doc-root pathAn option which takes a secondary parameter (a path)-i--installA boolean option (true/false)-*--Invalid option #!/bin/bash dr='' install=false skip=false for op ...

a='I am a simple string with digits 1234' pat='(.*) ([0-9]+)' [[ "$a" =~ $pat ]] echo "${BASH_REMATCH[0]}" echo "${BASH_REMATCH[1]}" echo "${BASH_REMATCH[2]}" Output: I am a simple string with digits 1234 I am a simple string with digits 1234

This counts the number of lines in a big file with wc -l while simultaneously compressing it with gzip. Both run concurrently. tee >(wc -l >&2) < bigfile | gzip > bigfile.gz Normally tee writes its input to one or more files (and stdout). We can write to commands instead of fil...

The following function reads an entire file into a new string and returns it: (defun read-file (infile) (with-open-file (instream infile :direction :input :if-does-not-exist nil) (when instream (let ((string (make-string (file-length instream)))) (read-sequence string instr...

Quotes will be output as-is: echo "Some Text" "Some Text" Comment tokens are ignored: echo Hello World REM this is not a comment because it is being echoed! Hello World REM this is not a comment because it is being echoed! However, echo will still output var...

SET TEST=0 IF %TEST% == 0 ( echo TEST FAILED ) ELSE IF %TEST% == 1 ( echo TEST PASSED ) ELSE ( echo TEST INVALID )

FIND command can scan large files line-by-line to find a certain string. It doesn't support wildcards in the search string. find /i "Completed" "%userprofile%\Downloads\*.log" >> %targetdir%\tested.log TYPE scan2.txt | FIND "Failed" /c && echo Scan fai...

The following script shows more advanced split file technique, where FOR function loops through a list of files in a directory, and each file content is piped to FINDSTR that looks for a string containing substring var preceded by undefined number of spaces and superseded by any extra text. Once fou...

Configuring the Primary Server Requirements: Replication User for replication activities Directory to store the WAL archives Create Replication user createuser -U postgres replication -P -c 5 --replication + option -P will prompt you for new password + option -c is for max...

To download NetBeans IDE just visit the NetBeans site and download the proper version of the IDE based on your OS, Architecture and technologies. You can select from the following technologies: Java SE. Supports all standard Java SE development features as well as support for NetBeans Platform ...

Renders text as justified paragraphs. REQUIRES the example Justified text Example render Top paragraph has setting.compact = true and bottom false and line spacing is 1.2 rather than the default 1.5. Rendered by code usage example bottom of this example. Example code // Requires justified...

When we’re first starting our work, we have to decide if this is a separate area of work we’re working on, or is this part of an existing line of work. If it’s existing, we can work off of that branch. If it’s new, we’ll start a new branch. Our workflow then is: hg branch MyNewFeature work wo...

You can have functions in the PS1 variable, just make sure to single quote it or use escape for special chars: gitPS1(){ gitps1=$(git branch 2>/dev/null | grep '*') gitps1="${gitps1:+ (${gitps1/#\* /})}" echo "$gitps1" } PS1='\u@\h:\w$(gitPS1)$ ' It will...

class ImageCreationExample { static Image createSampleImage() { // instantiate a new BufferedImage (subclass of Image) instance BufferedImage img = new BufferedImage(640, 480, BufferedImage.TYPE_INT_ARGB); //draw something on the image paintOnI...

public static void saveImage(String destination) throws IOException { // method implemented in "Creating a simple image Programmatically and displaying it" example BufferedImage img = createSampleImage(); // ImageIO provides several write methods with different outputs ...

static void setupQualityHigh(Graphics2D g2d) { g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY); // many other RenderingHints KEY/VALUE pairs to specify } ...

We can just do simple replacement of separators from space to new line, as following example. echo $sentence | tr " " "\n" It'll split the value of the variable sentence and show it line by line respectively.