C - split string using multiple delimiters in C

How to write a function that split a string using multiples delimiters, which could be char like ',' and could be string like "or".

For example, for the string char * string = "a or b or c, 8", I would like to print :

a 
b
c
8

I suggest that you first use strtok with the delimiter string " ," and then filter out tokens which have a special meaning, such as "or".

Here is an example:

#include <stdio.h>
#include <string.h>

int main( void )
{
    char string[] = "a or b or c, 8";
    const char *delim = " ,"; 
    char *token;

    token = strtok( string, delim );

    while ( token != NULL )
    {
        if ( strcmp( token, "or" ) != 0 )
        {
            printf( "%s\n", token );
        }

        token = strtok( NULL, delim );
    }
}

This program has the following output:

a
b
c
8

Note that strtok requires that the string is writable, because it writes null characters into the string. Therefore, you cannot use a string literal such as

char *string = "a or b or c, 8";

That is why I am using a writable array instead:

char string[] = "a or b or c, 8";

If you want your code to also work on string literals, then you cannot use strtok, but will have to use other functions instead, such as strpbrk.

void printsubstr(const char *start, const char *end, int printEmpty)
{
    if(printEmpty || start < end)
    {
        printf("\"");
        while(start < end && *start) printf("%c", *start++);
        printf("\"\n");
    }
}

void print(const char *str, const char *delim, int printEmpty)
{
    const char *found;
    size_t delimlen = strlen(delim);

    while((found = strstr(str, delim)))
    {
        printsubstr(str, found, printEmpty);
        str = found + delimlen;
    }
    printsubstr(str, str + strlen(str), printEmpty);
}

int main(void)
{
    print( "ormirror razor error", "or", 1);
    printf("-----------------------\n");
    print( "ormirror razor error", "or", 0);
}

You can use a simple function like this to split a string by multiple delimiters:

void split_and_or(char *str) {
    const char *delim = "and or";
    char *token;
    token = strtok(str, delim);
    while (token != NULL) {
        printf("%s\n", token);
        token = strtok(NULL, delim);
    }}

and in main:

int main() {
    char str[] = "a or b and c or d";
    split_and_or(str);
    return 0;                                                                       
}

However this code only works for Strings that do not contains charachters from the previous delimiters, so you can not use 'o' as one because the delimiter "or" contains 'o'.