replacing string with character in C

Question

The code takes user input(html tag)

ex:
<p> The content is &nbsp; text only &nbsp; inside tag </p>

gets(str);

Task is to replace all   occurences with a newline("\n")

while((ptrch=strstr(str, " ")!=NULL)
{
  memcpy(ptrch, "\n", 1);
}

printf("%s", str);

The code above replaces only first character with \n.

Query is how to replace entire   with \n or how to set rest of nbsp; to something like empty character constant without terminating string with null pointer('\0').

Answer 1

You're almost there. Now just use memmove to move the memory left to the new line.

char str[255];
char* ptrchr;
char* end;

gets(str); // DANGEROUS! consider using fgets instead
end = (str + strlen(str));

while( (ptrch=strstr(str, " ")) != NULL)
{
    memcpy(ptrch, "\n", 1);
    memmove(ptrch + 1, ptrch + sizeof(" ") - 1, end-ptrchr);
}

printf("%s", str);

Answer 2

Instead of memcpy you could directly set the character to '\n': *ptchr = '\n'; And after that use memmove to move the rest of the line left - you replaced 6 characters with 1, so you have to move the line by 5 characters.

Answer 3

Code

    char * ptrch = NULL;
    int len =0;
    while(NULL != (ptrch=strstr(str, " ")))
    {
      len = strlen(str) - strlen(ptrch);
      memcpy(&str[len],"\n",1);
      memmove(&str[len+1],&str[len+strlen(" ")],strlen(ptrch ));   
    }