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Full Discussion: Perl : How is file handling working here??
Top Forums Shell Programming and Scripting Perl : How is file handling working here?? Post 302831881 by balajesuri on Friday 12th of July 2013 06:19:17 AM
Old 07-12-2013
Everytime you do read from a filehandle and store it in a scalar variable, then one line of input is read. (By one line, I mean the data until the next record separator).

Here is how it works internally:
When you open a filehandle, lets say, there's a mark that is at the beginning of file. The first time $rec = scalar <$INF> is encountered, the first line from file is read and referred by $rec. Now, the mark that we spoke of earlier, is at the character just after newline character (assuming newline as the default record separator). Now again when $rec = scalar <$INF> is encountered, one more line of data is read.

In the example code you provided in your post, a wrapper routine "readfile" reads one line of data and prints it.

The usual way of reading a file is to use a loop. Then again, that depends on what you really want to do:

Code:
open FH, "< /path/to/file";
while ($rec = <FH>) {
    print $rec;
}
close FH;

 

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LEARN ABOUT REDHAT

play

play(1) 						      General Commands Manual							   play(1)

NAME

       play - play any sound file to audio device

       rec  - record audio to any sound file format

SYNOPSIS

       play [fopts] infile [effect]

       rec [fopts] outfile [effect]

DESCRIPTION

       This manual page briefly documents the play and rec commands.

       play  and  rec are programs that allow you to play and record different types of sound files from the command line.  They are front ends to
       the more general sox(1) package.  Normally, the play command will automatically detect the type and other parameters of the  soundfile.	If
       it can't do so, the parameters can be changed through options.

OPTIONS

       A summary of common options are included below.	For a complete description of options and their values, see the sox(1) man page.

       -c [channels], --channels=[channels]
	      Define the number of channels in the file.

       -d [device], --device=[device]
	      Specify a different device to play the sound file to.

       -f [format], --format=[format]
	      Specify bit format of the sample. One of s, u, U, A, a, or g.

       -r [rate], --rate=[rate]
	      Specify the sample rate of the audio data (samples per second).

       -s [size], --size=[size]
	      Specify the width of each sample.  One of b, w, l, f, d, or D.

       -t [type], --type=[type]
	      Specify audio file format to use.  Useful if it can not be automatically determined.

       -v [volume], --volume=[volume]
	      Change the audio volume

       -x , --xinu
	      Reverse the byte order of the sample (only works with 16 and 32-bit data).

       -h, --help
	      Show summary of options.

       --version
	      Show version of play/rec.

       Description of effects are described in the
	      sox(1) man page.

SEE ALSO

	sox(1)
	soxexam(1)

AUTHOR

       This manual page was written by Guenter Geiger <geiger@iem.mhsg.ac.at>, for the Debian GNU/Linux system.

       Updates by Anonymous.

								 December 11, 2001							   play(1)
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