# Script runs ok alone, broken pipe when piped to head? **URL:** \ **Category:** Ruby\ **Created:** [March 13, 2008, 11:50pm UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867 "2008-03-13T23:50:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![daz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/87869e/32.png) [@daz](https://www.ruby-forum.com/u/daz)\ **Post date:** [March 13, 2008, 11:50pm UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867/1 "2008-03-13T23:50:25Z")
Maybe I need to close the file or something? This invokation runs fine, but generates _so_ much output: ruby -rubygems excelparse.rb stuff.xls so I piped it to head and it bombs: ruby -rubygems excelparse.rb stuff.xls|head Row: 0 Cell: 0\> Dispapp Row: 0 Cell: 1\> Iprc Row: 0 Cell: 2\> UH tag Row: 0 Cell: 3\> Weight Row: 0 Cell: 4\> Tags removed Row: 0 Cell: 5\> Disk removed or wiped Row: 1 Cell: 0\> 80118 Row: 1 Cell: 1\> 1173 Row: 1 Cell: 2\> 961SU Row: 2 Cell: 0\> 80118 excelparse.rb:19:in `write': Broken pipe (Errno::EPIPE) from excelparse.rb:19:in`puts’ from excelparse.rb:19 from excelparse.rb:15:in `each' from excelparse.rb:15 from /usr/lib/ruby/gems/1.8/gems/parseexcel-0.5.2/lib/parseexcel/worksheet.rb:143:in`each’ from /usr/lib/ruby/gems/1.8/gems/parseexcel-0.5.2/lib/parseexcel/worksheet.rb:143:in `each’ from excelparse.rb:11 Any hints? The script itself is a minor mod of the example given at the parseexcel site (see below). Mahalo, Dave cat excelparse.rb require ‘parseexcel’ #Open the excel file passed in from the commandline workbook = Spreadsheet::ParseExcel.parse(ARGV[0]) #Get the first worksheet worksheet = workbook.worksheet(0) j=0 #cycle over every row worksheet.each { |row| i=0 if row != nil #cycle over each cell in this row if it’s not an empty row row.each { |cell| if cell != nil #Get the contents of the cell as a string contents = cell.to\_s(‘latin1’) puts “Row: #{j} Cell: #{i}\> #{contents}” end i = i+1 } end j=j+1 } ---
**Author:** ![daz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/87869e/32.png) [@daz](https://www.ruby-forum.com/u/daz)\ **Post date:** [March 14, 2008, 12:01am UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867/2 "2008-03-14T00:01:34Z")
Hi, On Fri, Mar 14, 2008 at 9:34 AM, Dave B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > `each' from /usr/lib/ruby/gems/1.8/gems/parseexcel-0.5.2 /lib/parseexcel/worksheet.rb:143:in `each’ > from excelparse.rb:11 > > Any hints? The script itself is a minor mod of the example given at > the parseexcel site (see below). It’s a very random guess, but is the EPIPE possibly happening because `head’ closed the connection after reading 10 lines? What happens if you run it like this…? ruby -rubygems excelparse.rb stuff.xls 2\>&1 | less Arlen ---
**Author:** ![daz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/87869e/32.png) [@daz](https://www.ruby-forum.com/u/daz)\ **Post date:** [March 14, 2008, 12:04am UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867/3 "2008-03-14T00:04:54Z")
Dave B. wrote: > so I piped it to head and it bombs: > > ruby -rubygems excelparse.rb stuff.xls|head > Row: 0 Cell: 0\> Dispapp > Row: 0 Cell: 1\> Iprc > Row: 0 Cell: 2\> UH tag > Row: 0 Cell: 3\> Weight > Row: 0 Cell: 4\> Tags removed > Row: 0 Cell: 5\> Disk removed or wiped > Row: 1 Cell: 0\> 80118 > Row: 1 Cell: 1\> 1173 > Row: 1 Cell: 2\> 961SU > Row: 2 Cell: 0\> 80118 > excelparse.rb:19:in `write’: Broken pipe (Errno::EPIPE) The “head” command reads and prints the first 10 lines of input (by default), then closes its input and exits. Your script is thus having it’s output stream closed which it isn’t expecting. The broken pipe is to be expected. ---
**Author:** ![daz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/87869e/32.png) [@daz](https://www.ruby-forum.com/u/daz)\ **Post date:** [March 14, 2008, 1:37am UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867/4 "2008-03-14T01:37:43Z")
On Mar 13, 1:04 pm, Mark B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Row: 1 Cell: 0\> 80118 So to get my script to act like a responsible command line citizen, I’d need to insert some error handling and return normally when the pipe breaks, right? Thanks for the info. Dave ---
**Author:** ![daz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/87869e/32.png) [@daz](https://www.ruby-forum.com/u/daz)\ **Post date:** [March 14, 2008, 9:51am UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867/5 "2008-03-14T09:51:13Z")
Dave B. wrote: > So to get my script to act like a responsible command line citizen, > I’d need to insert some error handling and return normally when the > pipe breaks, right? Since your script is, basically, in the business of doing IO, then yes, it is probably worth catching IO exceptions and exiting cleanly. ---
**Author:** ![daz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/87869e/32.png) [@daz](https://www.ruby-forum.com/u/daz)\ **Post date:** [March 16, 2008, 10:46pm UTC](https://www.ruby-forum.com/t/script-runs-ok-alone-broken-pipe-when-piped-to-head/131867/6 "2008-03-16T22:46:39Z")
On 14.03.2008 01:30, Dave B. wrote: > > > Row: 1 Cell: 0\> 80118 > > > So to get my script to act like a responsible command line citizen, > > > I’d need to insert some error handling and return normally when the > > > pipe breaks, right? Well, it depends. If you consider it an error when the script is not able to deliver all output the default behavior is ok. I usually do not bother to deal with this situation because I use head and tail from the command line only and I know what to expect there. Kind regards robert