From: Geoff Youngs <g@...>
Date: 2004-07-03T01:31:15+09:00
Subject: Re: Help with one-liner

Philip Mateescu wrote:

> My one liner sample:
>
> $ ping localhost | ruby -e '$<.readlines.each { |line|  line.chomp!(); 
> puts(line + "---\n");  }'
>
> I would expect it to put --- at the end of each line. Instead it 
> replaces the first 3 chars of each line with "---"
>
[snip]

> What am I doing wrong? And why? :)

Probably line endings - windows line endings are "\r\n" - and chomp! 
seems to only be removing
the "\n", so the carriage return is returning the cursor to the 
beginning of the line before
trying to display the "---\n" string.

Try using line.rstrip! to remove all trailing whitespace, or 
line.chomp!("\r\n").

Unless you want to process the entire output of the ping command at 
once, using IO#each_line
might be better than IO#readlines.  Also, the "\n" at the end of the 
string isn't needed -
IO#puts is capable of adding one automatically.

HTH,


Geoff.