String split in c without changing original [closed] - c

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we have an school asignment to make a specific function of string split
the header and arguments of function is given cannot change them .
this function should split original by delimiter into array of string that store each part of string delimiter not included and in additon for each delimiter increase size
void stringSplit(const char *original, char result[50][256], int* size, char delim){
size_t begin = 0;
if(!original){
return;
}
for(size_t i=0; i<strlen(original);i++ ){
if (original[i] == delim){
int str_begin = 0;
for( ; begin < i; begin++ ){
result[*size][str_begin] = original[begin];
str_begin++;
}
(*size)++;
begin ++ ;
}
}
}

Answer 1

The idea is OK, but you have a couple of errors:
Your string copies are not '\0'-terminated. Also you are not taking into
account when multiple delimiters follow in a row.
If you are not allowed to use
functions like strchr and strncpy, then you can do this:
size_t str_begin = 0;
*size = 0; // the user may have passed an uninitialized int variable
for(size_t i = 0; original[i] && *size < 50; ++i)
{
if(original[i] == delim)
{
size_t sublen = i - str_begin;
if(sublen == 0)
{
// skip delimiter, last character was also a
// delimiter and/or the first character in
// original is a delimiter
str_begin++;
continue;
// or if you want to have empty words instead of skipping
// results[*size] = 0;
// (*size)++;
}
if(sublen > 256)
sublen = 256;
for(size_t j = 0; j < sublen; ++j)
result[*size][j] = original + str_begin + j;
result[*size][j] = 0; // \0-terminating string
(*size)++;
str_begin = i + 1; // updating str_begin to next char
}
}

Answer 2

The straight forward way of doing so is - as suggested by Barmar - to make a copy of the original string and then work with strtok() and strcpy.
Alternatively, you could use strchr in a loop to find the delimiters and memcpy to copy the memory between the previous delimiter and the next one. See the following code, which also takes the boundaries of the result array into account:
void stringSplit(const char *original, char result[50][256], int *size, char
delim)
{
if(!original){
return ;
}
*size = 0;
const char* nextDelim;
const char* prevDelim = original;
do {
nextDelim = strchr(prevDelim,delim);
size_t len = nextDelim ? (nextDelim - prevDelim) : strlen(prevDelim);
if (len >= 256) {
len = 256-1;
}
memcpy(result[*size],prevDelim,len);
result[*size][len] = '\0';
(*size)++;
prevDelim = nextDelim ? nextDelim+1 : NULL;
}
while(nextDelim && *size < 50);
}
int main() {
char result[50][256];
int size;
stringSplit("Hello, this, is", result, &size, ',');
return 0;
}
Hope it helps.