Presumably you want to do this to avoid suid script restrictions. Here are a couple of options.

#!/usr/bin/perl
die Usage: ldap-group [-p] trans \n" unless @ARGV;
for my $arg(@ARGV) {
    die "Invalid $arg\n" unless $arg =~ m/^[A-Za-z]+$/;
}
exec("/opt/bin/techweb-changes.pl",@ARGV);
[download]

To do it in C it would be easiest to use a regex library

#include <regex.h>

/*
 * Match string against the extended regular expression in
 * pattern, treating errors as no match.
 *
 * return 1 for match, 0 for no match
 */

int
match(const char *string, char *pattern)
{
    int    status;
    regex_t    re;

    if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB) != 0) {
        return(0);      /* report error */
    }
    status = regexec(&re, string, (size_t) 0, NULL, 0);
    regfree(&re);
    if (status != 0) {
        return(0);      /* report error */
    }
    return(1);
}
[download]

I apologize I'm not following your C script very well, I used to be good in C, but I haven't used it for about 3 years. Could you make the script easier to understand.

Its not a script, it is a single function called match() You pass match two arguments - one is the string you want to check, the other the regex patern you want that string to match. The regex pattern is shown in the Perl example. The function returns 1 if it matches. I don't know how it could be simpler.

[root@devel3 root]# cat test.c
#include <stdio.h>
#include <regex.h>

int
main(int argc, char *argv[])
{
  int i;
  char *pat = "^[A-Z]+$";
  printf("Got %d args\n", argc-1 ); /* first arg prog name */
  for( i=1; i<argc; i++ ) {
      printf("Got %s\n",argv[i]);
      if ( match( argv[i], pat ) ) {
          printf("-->Match %s\n", pat);
      }
      else {
          printf("***Fail\n");
      }
  }
  return 0;
}

int
match(const char *string, char *pattern)
{
    int    status;
    regex_t    re;

    if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB) != 0) {
        return(0);      /* report error */
    }
    status = regexec(&re, string, (size_t) 0, NULL, 0);
    regfree(&re);
    if (status != 0) {
        return(0);      /* report error */
    }
    return(1);
}

[root@devel3 root]# gcc test.c
[root@devel3 root]# ./a.out 123 ABC abc ABC123
Got 4 args
Got 123
***Fail
Got ABC
-->Match ^[A-Z]+$
Got abc
***Fail
Got ABC123
***Fail
[root@devel3 root]#
[download]

I have no comprehension why you want to do data validation in C before you call a Perl script. Surely the Perl does data validation????? If so just use your C wrapper to exec the Perl script. End of story.

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Because of security, my Perl will be ran has root so I'm using C to put a security blanket around it. In the perl script of change to the Effective UID which is root.

Either use the setuid function of POSIX, or else study perlvar for $< and $>, which can be used to change the real and effective UIDs in Perl itself, eliminating the need for a C wrapper.

Even if it didn't have that built in, you could plan on using Inline::C to get access to useful C functionality directly in Perl.

Remember that Perl has had a long life as a system administration tool on *nix, so you should expect that it has features which are useful for that, you just have to look for them.