Feature #5219: Array#pack should warn (or raise) if an invalid pack string is given

• Status: Closed
• Assignee: drbrain (Eric Hodel)
• Target version: 2.0.0

[drbrain (Eric Hodel)]

If garbage characters are inserted into the pack string ruby ignores them:

$ ruby19 -e 'p [1, 2, 3].pack("*N")'
"\x00\x00\x00\x01"

$ ruby19 -e 'p [1, 2, 3].pack("yN")'
"\x00\x00\x00\x01"

Ruby should at least warn like printf when -w is active:

$ ruby19 -we 'printf "%d %d", 1, 2, 3'
-e:1: warning: too many arguments for format string

A future version could raise an exception.

See also: https://github.com/rubinius/rubinius/issues/1127

[ko1 (Koichi Sasada)]

• Tracker changed from Bug to Feature

[mame (Yusuke Endoh)]

• Status changed from Open to Assigned
• Assignee set to drbrain (Eric Hodel)

drbrain,

Ruby should at least warn like printf when -w is active:

Agreed. Could you offer a patch?
I think you can commit it, unless there is objection.

--
Yusuke Endoh [e-mail]

[drbrain (Eric Hodel)]

• File pack.c.warn_on_unknown_directive.patch pack.c.warn_on_unknown_directive.patch added

I was helping someone else write a patch, but they have gone missing.

Can you check this patch?

[drbrain (Eric Hodel)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r35292.
Eric, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• pack.c (pack_pack): Warn when an invalid character is found in the
  format string when $VERBOSE is true. [ruby-trunk - Feature #5219]
• pack.c (pack_unpack): ditto
• test/ruby/test_pack.rb (class TestPack): Test for warnings on
  invalid format characters.