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Full Discussion: AWK for a beginner
Top Forums Shell Programming and Scripting AWK for a beginner Post 302703343 by Corona688 on Wednesday 19th of September 2012 03:55:45 PM
Old 09-19-2012
The funny thing about awk is that it comes with its own built-in while loop.

A program that looks like this:
Code:
awk '/regex/ { print $1 }' filename

Works like this pseudocode:

Code:
FS=" "; // Field separator
RS="\n";  // Record separator
NR=1; // Total number of lines read

for(FNR=1; !end_of_file("filename");  FNR++, NR++)
{
        $0=read_line("filename", RS); # Read until next RS character
        tokens[]=split($0, FS); # Split "a b c" into "a", "b", "c"

        if(match(/regex/, $0)) print(tokens[1]);
}

FS and RS are special variables in awk which you can use to change what awk thinks columns and newlines are.

NR and FNR are special variables which count the total number of lines, and the line number in the current file respectively.
 

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LEARN ABOUT OPENSOLARIS

dotty

DOTTY(1)                                                      General Commands Manual                                                     DOTTY(1)

NAME

       dotty - A Customizable Graph Editor

SYNOPSIS

       dotty [ -V ] [ file ]

DESCRIPTION

       dotty is a graph editor for the X Window System.  It may be run as a standalone editor, or as a front end for applications that use graphs.
       It can control multiple windows viewing different graphs.

       dotty is written on top of dot and lefty.  lefty is a general-purpose programmable editor for technical pictures.  It has  an  interpretive
       programming  language similar to AWK and C.  The user interface and graph editing operations of dotty are written as lefty functions.  Pro-
       grammer-defined graph operations may be loaded as well.  Graph layouts are made by dot, which runs as a separate process that  communicates
       with lefty through pipes.

USAGE

       The file name is optional. If present, the graph contained in that file is displayed in the dotty window.

OPTIONS

       -V     Prints the version.

SEE ALSO

       dot(1), lefty(1)
       dotty user guide.

                                                                                                                                          DOTTY(1)
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