/* stringutil.c */

/* String utilities */

#include "os.h"
#include "copyright.h"
#include "interface.h"
#include "globals.h"


int string_compare (const char *s1, const char *s2)
{
  while (*s1 && *s2 && DOWNCASE (*s1) == DOWNCASE (*s2))
    s1++, s2++;

  return (DOWNCASE (*s1) - DOWNCASE (*s2));
}

int string_prefix (const char *string, const char *prefix)
{
  if (!string || !prefix)
    return 0;
  while (*string && *prefix && DOWNCASE (*string) == DOWNCASE (*prefix))
    string++, prefix++;
  return *prefix == '\0';
}

/* accepts only nonempty matches starting at the beginning of a word */
const char *string_match (const char *src, const char *sub)
{
  if (*sub != '\0') {
    while (*src) {
      if (string_prefix (src, sub))
        return src;
      /* else scan to beginning of next word */
      while (*src && isalnum ((int)*src))
        src++;
      while (*src && !isalnum ((int)*src))
        src++;
    }
  }
  return 0;
}

char *strupper (const char *s)
{
  static char buf1[BUFFER_LEN];
  char *p;

  strcpy (buf1, s);
  for (p = buf1; *p; p++)
    *p = UPCASE (*p);
  return buf1;
}