Re: bash conditional expressions

[Michael J. Baars]

On Wed, 2021-11-17 at 14:06 +0200, Ilkka Virta wrote:
> On Wed, Nov 17, 2021 at 1:33 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
> > On Nov 17 2021, Michael J. Baars wrote:
> > 
> > 
> > 
> > > When -N stands for NEW, and touch (-am) gives you a new file
> > 
> > 
> > 
> > It doesn't.  The file hasn't been modified after it was last read.
> 
> touch creates the given file if it doesn't previously exist. Immediately 
> afterwards,it could be called "new" in the usual English meaning, and would 
> be new in thesense that nothing was done to it
> after it was created. But:
> $ echo $BASH_VERSION5.1.8(3)-maint
> $ rm foo.txt
> $ ls -l foo.txt
> ls: cannot access 'foo.txt': No such file or directory
> $ touch -am foo.txt
> $ if test -N foo.txt; then echo is new; else echo is NOT new; fi
> is NOT new
> 
> Of course "new" is not an exact concept, it could be defined e.g. to compare 
> the
> file timestamps with the current time.
> 
> 
> Anyway, the documentation doesn't seem to say 'test -N' tests if the file is 
> "new".

It seemed logical to assume that '-N' stands for 'new' in some way. The rest of 
the line does indeed not imply '-N' to be equivalent to 'new'.