Hi,

I have a script readbinary.sh with the following three lines

#!/bin/bash
var=`cat binaryfile`
echo $var

but if I run the file readbinary.sh > trial and do a diff

vimdiff trial binaryfile they are not the same. Moreover the
size of the two files are not the same.This is the case even
if I modify the script to read line by line. This prompts me
to think that shell variables have some pre-specified size.

Also, the discrepancy in the start of the two files binaryfile
and trial is even more baffling.

Please advise where I might be going wrong.

Thanks in advance
_Madhu

In article <f3fmt1$jrd$1@prometheus.acsu.buffalo.edu>,
Madhusudhanan Chandrasekaran <mc79@cse.buffalo.edu> wrote:

> Hi,
>
> I have a script readbinary.sh with the following three lines
>
> #!/bin/bash
> var=`cat binaryfile`
> echo $var
>
> but if I run the file readbinary.sh > trial and do a diff
>
> vimdiff trial binaryfile they are not the same. Moreover the
> size of the two files are not the same.This is the case even
> if I modify the script to read line by line. This prompts me
> to think that shell variables have some pre-specified size.
>
> Also, the discrepancy in the start of the two files binaryfile
> and trial is even more baffling.
>
> Please advise where I might be going wrong.
>
> Thanks in advance
> _Madhu

Since you didn't quote "$var", the shell will perform word splitting
(essentially replacing all runs of whitespace with a single space) and
wildcard processing.

Also, if there are any NUL characters in the file, they'll be discarded
by the shell.

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
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