On Tue, 20 Oct 2020 at 14:11, David Christensen <dpchr...@holgerdanske.com> wrote: > On 2020-10-19 04:55, Greg Wooledge wrote: > > On Sat, Oct 17, 2020 at 03:01:13PM -0700, David Christensen wrote:
> >> I try to use all lower case letters for variable names and all upper case > >> letters for constants. > > ALL_UPPER_CASE is reserved for internal shell variables, and environment > > variables. > Please provide a citation (for Bourne shell scripts). Maybe POSIX.1-2017 is what you're asking for? https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap01.html """ POSIX.1-2017 defines a standard operating system interface and environment, including a command interpreter (or "shell"), and common utility programs to support applications portability at the source code level. """ https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html """ Environment variable names used by the utilities in the Shell and Utilities volume of POSIX.1-2017 consist solely of uppercase letters, digits, and the <underscore> ( '_' ) [...] The name space of environment variable names containing lowercase letters is reserved for applications. [...] It is unwise to conflict with certain variables that are frequently exported by widely used command interpreters and applications: [...] """
