How to get piped input to ruby -e on command line?
Ruby treats your line as a comment because it starts with a #.
This would work:
echo "My String" | ruby -e "puts gets.downcase"Output:
my stringI've used Kernel#gets instead of STDIN.gets:
Returns (and assigns to $_) the next line from the list of files in ARGV (or $*), or from standard input if no files are present on the command line
If you want to process each line, you could use the -p flag. It's like wrapping your script in a while gets(); ... end; puts $_ block. Ruby reads each input line into $_, evaluates your script and outputs $_ afterwards:
echo "Foo\nBar\nBaz" | ruby -pe '$_.downcase!'Output:
foobarbaz