Eric, > using [] around range expressions is also a valid workaround. The solution > still is POSIX-compliant; it's just that you are transliterating [ and ] > to themselves in a working tr.
But a workaround like this leads to confusing code. The first time I saw this use of tr '[A-Z]' '[a-z]' in a piece of shell code without comments, about a year or two ago, I was very confused: Is 'tr' now accepting ranges like 'grep' does? Does 'tr' use the collation element order? Was the programmer drunk? > I'd rather use a simple idiom (always use []) than a more complex idiom > (play with PATH to find a more-compliant tr) when both are valid > workarounds. Well, I disagree. For me, the gnulib philosophy applied to shell scripts gives better results. For example, in 'gnulib-tool' we have 168 lines of code that provide a working 'echo' without dangerous loopholes. Then in the following 5000 lines of code, the problem is gone, and I can concentrate on gnulib-tool logic (mostly). Yes, I know, in case of doubt it is better to consult the Autoconf manual, but over time I want to arrive at a programming style where I can minimize these lookups and navigate safely. Likewise, in an Autoconf generated 'configure' file you set LC_ALL=C at the beginning, rather than having to think about whether it is necessary at every command later. In other words, if a portability problem can be fixed once and for all, then fix it once and for all. Bruno
