Removed discussion of `[[:<:]]' and `[[:>:]]' since they do
not seem to be in the glibc implementation.
As per
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=295666
> The regex.7.gz mentions that [[:>:]] and [[:<:]] are available to designate word boundaries.
> However, neither grep nor sed, which are build on the standard libc regcomp do recognise this syntax.
> Moreover, the small program here
>
> #include <regex.h>
> #include <sys/types.h>
> #include <iostream>
>
> using namespace std;
>
> int main()
> {
> regex_t RE;
> int err_code = regcomp(&RE, "[[:<:]]",
> REG_EXTENDED);
> char Buffer[100];
> if(err_code) {
> regerror(err_code, &RE, Buffer, 100);
> cerr << "Error : " << Buffer << endl;
> }
> }
>
>
> produces the following error message:
>
> Error : Invalid character class name
Michael Kerrisk