Re: test binary

[Brian Dessent]

Kenneth J Vojtech wrote:

> In zLinux for o/s390 (SuSe v 8 64 bit) is a binary 'test' that we use to
> test for the existence of files.  One of our tests uses a wildcard to check

You are probably using the bash builtin command 'test' here and not the
binary /bin/test that is a part of coreutils.  Use the command "type
test" to see if this is the case.  That does not change the nature of
your problem, though.

> for any *.hdr files in a certain directory.  When there is more than one
> *.hdr file in this directory, the test fails with an exit 2, so we are not
> processing any files.  Is there an option that will allow the test command
> to end with exit 0 if multiple files are found?  Or is this a bug?

This is how 'test -e' is designed to work, that is, to take a single
filename to test for existence.  When you use a wildcard, the shell
first expands that into multiple arguments before invoking the command,
which has no idea that a wildcard was ever involved.  All it knows is
that where it expected a single thing it got more than one, e.g. "test
-e 123.hdr 456.hdr", which is not valid syntax.

I suggest that you use something like the following to see if one or
more files matching a wildcard are present:

test x`find . -maxdepth 1 -name \*.hdr -printf yes -quit" = xyes

This invokes find to search the directory '.' for files matching *.hdr. 
Because we want find to do the searching and not the shell, the *
wildcard must be quoted so that the shell doesn't expand it as above. 
-maxdepth 1 causes find not to recurse into subdirectories.  When it
finds the first file matching that pattern it will print "yes" and exit
without further work.  If no such file is found it will print nothing,
which is why both arguments to '=' are prefixed with 'x'.  Otherwise,
test would be called as "test = yes" on a non-match which is invalid
syntax -- the left hand side argument is missing.  You could skip the
-printf and test the output against the empty string, but then if one of
the found files had a space in its name you would end up invoking test
with invalid syntax.  You could play quoting games to get around that
but I find using -printf to be simpler.  YMMV.

Brian