Hi Wolfgang,
this really is an interesting addition!
Syntax: env regex [-g] [-s subst] regex name [...]
The code is based on SLRE (http://slre.sourceforge.net/) which provides a tiny subset of Perl regular expressions.
Without options, this will implement regex pattern matching on environment variables. Variables with matching values will be printd as with "env print", so this basicly performs a "grep" on the given list of variables.
Ok, this usage looks fine.
With "-s subst", the matching pattern gets replaced with the string given in "subst". Back references '\0' ... '\9' are allowed, where '\0' stands for the whole matched string, and '\1', '\2', ... are replaced with the first, second, ... sub-pattern.
"-g" allows for global replacement.
But IMHO this usage doesn't really belong into the "env" command. It much rather is a further operation of the setexpr command:
set environment variable as the result of eval expression", name value1 <op> value2\n" - set environment variable 'name' to the result of the evaluated\n" express specified by <op>. <op> can be &, |, ^, +, -, *, /, %"
We could add the <op>erations for regsubst and regsubstg. For actual names for the operations, I'm somewhat unsure. Maybe "function like", i.e. "regsubst(string, pattern, replacement)" and "regsubstg(string, pattern, replacement)"?
Examples: => setenv foo abcdefghijklmnop => env reg 'A' '[bdgmo]' foo => env reg -s 'A' '[bdgmo]' foo foo=aAcdefghijklmnop => env reg -g -s 'B' '[bdgmo]' foo foo=aAcBefBhijklBnBp => env reg -g -s '\2--\1' '(Be).*(kl)' foo foo=aAckl--BeBnBp
So I'd vote for
=> setenv result regsubst($foo, '[bdgmo]', 'A')
What do you think?
Cheers Detlev