Question

I’m trying very hard to figure out a way to parse a string and “highlight” the search term in the result by making it uppercase.

I’ve tried using strstr and moving a pointer along and “toupper”ing the characters, to no avail.

char * highlight( char *str, char *searchstr ) {

 char *pnt=str;
 int i;

 pnt=strstr(str,searchstr);

 while(pnt){

 printf("ststr retured: %s\n", pnt);

 for(i=0;i<strlen(searchstr);i++) {
  printf("%c",toupper(pnt[i]));
 }
 printf("\n"); 
 pnt=pnt+strlen(searchstr);
 pnt=strstr(pnt,searchstr);

}

 return str;

}

Any advice is greatly appreciated.

Answer 1

Since Schot mentioned every occurrence:

#include <string.h>

char *highlight(char *str, char *searchstr) {

  char *pnt = str;

  while (pnt = strstr(pnt, searchstr)) {
    char *tmp = searchstr;
    while(*(tmp++)) { *pnt = toupper(*pnt); pnt++; }
  }
  return str;

}

int main() {
  char s[] = "hello world follow llollo";
  char search[] = "llo";
  puts(highlight(s, search));
  return 0;
}

output is:

$ ./a.out 
heLLO world foLLOw LLOLLO