Re: [dpdk-dev] [PATCH] build: use cat instead of more

[Bruce Richardson <bruce.richardson@intel.com>]

On Mon, Apr 01, 2019 at 01:24:20PM +0200, Thomas Monjalon wrote:
> 01/04/2019 12:36, Ali Alnubani:
> > This is to fix a build error with meson that is caused
> > by using the 'more' command to read the VERSION file. The error:
> > 
> >     config/meson.build:10:10: ERROR:  String
> >     '::::::::::::::\n<RTE_SDK_PATH>VERSION\n::::::::::::::\n19' cannot be
> >     converted to int
> > 
> > The command 'more' prints the file name before the actual
> > contents of the file when it's being run without a controlling terminal.
> > This could happen in CI environments.
> > 
> > Please refer to:
> > https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/tree/text-utils/more.c
> > 
> > The cat command can still be found on Windows if the ports of GNU
> > utilities are installed.
> > 
> > Fixes: c04172b5f031 ("build: add single source of DPDK version number")
> > Fixes: d320fe56bd51 ("build: use version number from config file")
> > 
> > Signed-off-by: Ali Alnubani <alialnu@mellanox.com>
> 
> Acked-by: Thomas Monjalon <thomas@monjalon.net>
> 
> It is fixing a regression on Linux.
> I think we should take this fix urgently
> and think about Windows in a next step.
> 
> "more" is an interactive command, we should not use it.
> As suggested by Ali, we may require an extra dependency on Windows
> to get some GNU utilities. Or if no other tools are required,
> may we have a meson builtin to read a file?
> 
Should not need to do so. May I suggest using "find_program" function
instead of hard-coding the command. That allows a list of programs to be
specified and the first one found is used. Unfortunately, on windows the
direct equivalent of "cat" is "type" which is a built-in rather than
command as far as I can see, so find_program doesn't work for it. However,
the following should do:

version: run_command(find_program('cat', 'more'), files('VERSION')).stdout().strip()