String and String array Manipulation in c - c

Question

I'm trying to write a string spliter function in C.It uses space as delimiter to split a given string in two or more. It more like the split funtion in Python.Here is the code:-
#include <stdio.h>
#include <string.h>
void slice_input (char *t,char **out)
{
char *x,temp[10];
int i,j;
x = t;
j=0;
i=0;
for (;*x!='\0';x++){
if (*x!=' '){
temp[i] = *x;
i++;
}else if(*x==' '){
out[j] = temp;
j++;i=0;
}
}
}
int main()
{
char *out[2];
char inp[] = "HEllo World ";
slice_input(inp,out);
printf("%s\n%s",out[0],out[1]);
//printf("%d",strlen(out[1]));
return 0;
}
Expeted Output:-
HEllo
World
but it is showing :-
World
World
Can you help please?

Answer 1

out[j] = temp;
where temp is a local variable. It will go out of scope as soon as your function terminates, thus out[j] will point to garbage, invoking Undefined Behavior when being accessed.
A simple fix would be to use a 2D array for out, and use strcpy() to copy the temp string to out[j], like this:
#include <stdio.h>
#include <string.h>
void slice_input(char *t, char out[2][10]) {
char *x, temp[10];
int i,j;
x = t;
j=0;
i=0;
for (;*x!='\0';x++) {
if (*x!=' ') {
temp[i] = *x;
i++;
} else if(*x==' ') {
strcpy(out[j], temp);
j++;
i=0;
}
}
}
int main()
{
char out[2][10];
char inp[] = "HEllo World ";
slice_input(inp,out);
printf("%s\n%s",out[0],out[1]);
return 0;
}
Output:
HEllo
World

Answer 2

http://www.cplusplus.com/reference/clibrary/cstring/strtok/
From the website:
char * strtok ( char * str, const char * delimiters ); On a first
call, the function expects a C string as argument for str, whose first
character is used as the starting location to scan for tokens. In
subsequent calls, the function expects a null pointer and uses the
position right after the end of last token as the new starting
location for scanning.
Once the terminating null character of str is found in a call to
strtok, all subsequent calls to this function (with a null pointer as
the first argument) return a null pointer.
Parameters
str C string to truncate. Notice that this string is modified by being
broken into smaller strings (tokens). Alternativelly [sic], a null
pointer may be specified, in which case the function continues
scanning where a previous successful call to the function ended.
delimiters C string containing the delimiter characters. These may
vary from one call to another. Return Value
A pointer to the last token found in string. A null pointer is
returned if there are no tokens left to retrieve.
Example
/* strtok example */
#include <stdio.h>
#include <string.h>
int main ()
{
char str[] ="- This, a sample string.";
char * pch;
printf ("Splitting string \"%s\" into tokens:\n",str);
pch = strtok (str," ,.-");
while (pch != NULL)
{
printf ("%s\n",pch);
pch = strtok (NULL, " ,.-");
}
return 0;
}
You can use this function to split string into tokens - there is no need to use some own functions. Your code looks like garbage, please format it.
Your source propably would look like this:
char *
strtok(s, delim)
char *s; /* string to search for tokens */
const char *delim; /* delimiting characters */
{
static char *lasts;
register int ch;
if (s == 0)
s = lasts;
do {
if ((ch = *s++) == '\0')
return 0;
} while (strchr(delim, ch));
--s;
lasts = s + strcspn(s, delim);
if (*lasts != 0)
*lasts++ = 0;
return s;
}