On 6 March 2017 14:09:39 GMT+00:00, Rob la Lau <r...@ohreally.nl> wrote: >On 06-03-17 14:18, Greg Wooledge wrote: >> You're misunderstanding. In a math context, which you are creating >here >> by using -eq, the word 'x' is interpreted as a variable name, which >may >> contain another variable name, and so on, until finally an integer is >> discovered. > >Thanks. Now that I know it, I can indeed find it in the docs. > >I guess this means that actually test and [ are 'broken': > >$ test "x" -eq "x" && echo "yes" || echo "no" >test: invalid integer 'x' >no
It is my understanding that [ is a standard command mandated by POSIX which may be implemented as an external command. It would be unreasonable to expect an external command to be able to introspect shell variables, and similarly I would be surprised to find a shell which does this substitution in the [ command. For that reason it would certainly break my usual expectations for how my scripts should run, and it might possibly become a source of bugs. In the case of [[ however, it is entirely understandable because it is expected that the shell does magic in that case (new parsing rules etc.). -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
