Re: shell script style in C++

From:
Juha Nieminen <nospam@thanks.invalid>
Newsgroups:
comp.lang.c++
Date:
Fri, 18 Jul 2008 16:29:57 GMT
Message-ID:
<9y3gk.112$4Z3.81@read4.inet.fi>
rudra wrote:

is it possible to test it as it is done in configure file? eg:

case "$host_arch" in
      i[3-9]86|x86|x86pc|k5|k6|k6-2|k6-3|pentium*|athlon*|i586-i686)
return 0 ;;
    *) return 1 ;;
instead of those casceding if-else?


  The more convoluted your regexp is, the harder it becomes to perform
the check in any other way than using a third-party regexp library.

  If you don't want to use a third-party regexp library, what you can do
is to create a simple array with your strings and then perform the
comparisons in a loop. This will be more limited than the regexp, but at
least you don't have to write an if block for every possible value.
Something like:

struct Value
{
    const char* const str;
    const int length;
};

const Value values[] = { { "i386", 4 }, { "k6-2", 4 }, ... };
const int valuesAmount = sizeof(values)/sizeof(values[0]);

for(int i = 0; i < valuesAmount; ++i)
    if(strncmp(sysptr, values[i].str, values[i].length))
    {
        t = 1;
        break;
    }

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