NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/bugs/4bsd/239

Internet Message Format | 1992-12-16 | 5.6 KB

Path: sparky!uunet!pipex!unipalm!uknet!edcastle!mfg
From: [e-mail] (M Gordon)
Newsgroups: comp.bugs.4bsd
Subject: Re: A serious bug in unix2dos/dos2unix
Message-ID: <[e-mail]>
Date: 16 Dec 92 09:26:46 GMT
References: <[e-mail]> <[e-mail]>
Organization: Edinburgh University
Lines: 189

[e-mail] (Jonathan Bayer) writes:

>[e-mail] (Haiying ZHANG) writes:


>>   I came across this bug a while ago. This has to do with using wild
>>card in file names with unix2dos/dos2unix.

>>   If you use a wild card in the file name, be it a single * or a ?
>>embedded in a pattern, these two handy utilities will wipe out your
>>entire current directory with the exception of the first file. It will
>>set all the rest of the file to size 0.

>>   Although the man page does mention anything about wild card in
>>filename making one believe that it is not supported, it should not in
>>any case cause serious damaging to your files. While I am at it, these
>>two programs look like a recompile of its DOS version. It should have
>>provided more - options such as -Rfp etc. as in cp.


>First, what system are you running on?  Second, what are you trying to do?
>On a Sun system the dos2unix command is designed to operate on ONE file only,
>sending the output to the second file specification.  The wild cards are
>expanded by the shell, and all the program sees is a long list of filenames.


Running dos2unix with wildcards is incorrect, but it still shouldn't
destroy all of the other files.  Having seen the source for dos2unix,
what it does (at least on the Sun version) is

    for each argument
      if it's an option
    process it
      else
    if it's the first time we've seen a filename
      open it for reading
    else
      open it for writing


This is definitely a bug - it will process the first file on the
command line, with output going into the last file, and truncate the
others to zero length.  I ended up writing a script to process
multiple files, which is appended below in a shar archive with a
manual page.  The script should be installed as dos2unixdir, with
a link to it called unix2dosdir.


--------------------------------------------------------------------------------
#    This is a shell archive.
#    Remove everything above and including the cut line.
#    Then run the rest of the file through sh.
#----cut here-----cut here-----cut here-----cut here-----
#!/bin/sh
# shar:    Shell Archiver
#    Run the following text with /bin/sh to create:
#    dos2unixdir.1
#    dos2unixdir
# This archive created: Wed Dec 16 09:20:28 1992
cat << \SHAR_EOF > dos2unixdir.1
.TH  "DOS2UNIXDIR" "1L" "14th November 1991" "uk.ac.ed.ee"  "LOCAL commands"
.SH NAME
dos2unixdir
.sp 1
unix2dosdir \- run conversion programs on directory trees.
.SH SYNOPSIS
\fBdos2unixdir\fP \fI[-v] input-dir [output-dir]\fP
.br
\fBunix2dosdir\fP \fI[-v] input-dir [output-dir]\fP
.SH DESCRIPTION
\fBDos2unixdir\fP copies the directory tree rooted at \fIinput-dir\fP
to \fIoutput-dir\fP,
running the command \fIdos2unix -ascii -7\fP on each one.
If \fIoutput-dir\fP is not given the files will be converted in place.
The \fI-v\fP option makes \fBdos2unixdir\fP print the name of each file
as it converts it.
.PP
\fBUnix2dosdir\fP is identical to \fBdos2unixdir\fP,
except that it runs \fIunix2dos -ascii -7\fP on the files.
.SH NOTES
If \fIoutput-dir\fP is not empty the converter will only be run on files
that have been copied from \fIinput-dir\fP.
To convert all of the files in a directory run \fBdos2unixdir\fP with one
directory argument.
.SH AUTHOR
[e-mail] : MFG
SHAR_EOF
cat << \SHAR_EOF > dos2unixdir
#!/bin/sh

# A function to make a directory hierarchy - mostly taken from X11 mkdirhier
mkdirhier ()
{
    parts=`echo $1 | sed 's/\(.\)\/\(.\)/\1 \2/g`

    path=""
    for d in $parts
    do
        if [ "$path" = "" ]
        then
            dir=$d
        else
            dir=$path/$d
        fi

        if [ ! -d $dir ]
        then
            [ "$verbose" = "yes" ] && echo "Making $dir"
            mkdir $dir
        fi

        path=$dir
    done
}


verbose=no
progname=`expr $0 : '.*/\(.*\)'`
conv_options="-ascii -7"
if [ "$progname" = "dos2unixdir" ]
then
    conv=dos2unix
elif [ "$progname" = "unix2dosdir" ]
then
    conv=unix2dos
else
    echo "Conversion program started with name $progname"
    echo "I only understand being started as dos2unixdir or unix2dosdir"
    exit 1
fi

if [ "$1" = "-v" ]
then
    verbose=yes
    shift
fi
topindir=$1
topoutdir=$2

if [ ! -d $topindir ]
then
    echo "$0: $topindir - not a directory or doesn't exist"
    exit 1
fi

# If the input directory is a symbolic link (e.g. ~/floppy) find won't
# follow it. Find doesn't have an option to make it follow symbolic
# links so the following hack is necessary.
[ -h $topindir ] && topindir="$topindir/."

if [ $# -eq 1 ]
then
    for infile in `find $topindir -type f -print`
    do
        [ "$verbose" = "yes" ] && echo $infile
        $conv $conv_options $infile $infile
    done
elif [ $# -eq 2 ]
then
    if [ ! -d $topoutdir ]
    then
        echo "$0: $topoutdir - not a directory or doesn't exist"
        exit 1
    fi

    for infile in `find $topindir -type f -print`
    do
        reloutfile=`expr $infile : "$topindir/\(.*\)"`
        reloutdir=`dirname $reloutfile`
        outdir=$topoutdir/$reloutdir
        baseoutfile=`basename $infile`
        outfile=$outdir/$baseoutfile
        [ ! -d $outdir ] && mkdirhier $outdir
        [ "$verbose" = "yes" ] && echo $outfile
        $conv $conv_options $infile $outfile
    done
else
    echo "usage: $0 [-v] input-directory [output-directory]"
    exit 1
fi
SHAR_EOF
#    End of shell archive
exit 0

--------------------------------------------------------------------------------
--
Michael Gordon - [e-mail] OR ee.ed.ac.uk
Computing Officer, EE Dept, Edinburgh University
It's not an optical illusion, it just looks like one