185063 - when generating dependent libraries, 'cut' is used, and it cares about spaces, when it should care about whitespace

Status: VERIFIED FIXED

(www.mozilla.org :: General, defect)

Description

[lidl]

User-Agent:       Mozilla/5.0 (X11; U; BSD/OS i386; en-US; rv:1.2.1) Gecko/20021204
Build Identifier: Mozilla/5.0 (X11; U; BSD/OS i386; en-US; rv:1.2.1) Gecko/20021204

In the "Building a Mozilla Release" document, there is a command line given for
generating a list of dependent libraries for unix machines.  It is requested the
output for that command line is appended to the specific readme file for the
build that you are constructing.

That is all well and fine, however, the command line that is used:

ldd mozilla-bin components/*.so | sort | uniq | grep = | grep -v "not found" 
     | cut -f 3 -d " " | sort | uniq

This command line has the unfortunately problem of relying on 'ldd' to only use
spaces in its whitespace output, and ignores other types of whitespace
characters, such as tab characters.

Using a smarter tool, such as 'awk' would be a better way of doing this step.
Simply replacing the 'cut -f 3 -d " "' with "awk '{print $3}'" will accomplish
this goal.  It will then treat whitespace as whitespace, and not care if it is
made up with a combination of space and tab characters.

This particular problem afftected me on BSD/OS 5.0, when attempting to package a
 recent version of the browser.  On previous versions of BSD/OS, the ldd command
only output spaces.  On BSD/OS 5.0, the output is separated by a combination of
spaces and tabs.

Further savings can be realized by harnessing the power of awk more fully:

ldd mozilla-bin components/*.so | awk '{if (/=/ && !/not found/) print $3}'
   | sort | uniq

This gets rid of the two grep invocations as well.  Getting rid of the first
sort and uniq invocations is also reasonable -- awk is pretty fast at processing
input, and not doing a first-pass reduction of the input data (the first sort |
uniq) is reasonable.


  

Reproducible: Always

Steps to Reproduce:
1. Run the command line in the "Building a Release document" on BSD/OS 5.0
2. Note that it fails to produce a list of valid dependency libraries.

Comment 1

[Chris P. Ross]

Yeah, this burned me on a BSD/OS 5.0 system.  To be more specific about the
exact nature of the problem, the BSD/OS 5.0 ldd outputs an additional SPACE
character before the first non-whitespace output.  This causes the cut to need
to be "-f 4" to work.
The suggested "awk {print $3}" however works just fine on BSD/OS 4.x and 5.0; as
does the longer awk invocation to eliminate the use of grep.

Comment 2

[hacker formerly known as [e-mail]]

-> mozilla.org

Comment 3

[hacker formerly known as [e-mail]]

The instructions have been updated to use the recommended awk sequence.

Comment 4

[lidl]

Actually, it appears that someone put an escaping bang (!) in the awk script,
which is NOT needed (and actually fouls things up), since it is already inside
a single-quoted string.

Comment 5

[Dave Miller [:justdave]]

->seawood since he fixed it last time

Comment 6

[hacker formerly known as [e-mail]]

The expression doesn't work on tcsh without escaping the bang.  The page has
been updated.