Concatenation of strings as char pointers
haven't used C in a while....so this might be really simple for most of you....
can someone please tell me how to concatenate two char * strings?
eg.
char * c1 = "SYSTEM PATH = "
char *c2 = getenv("PATH");
how do I concatenate c1 + c2 and put the result into a third char * variable?
Thanks very much.
that doesn't work here cos I guess the getenv function returns a pointer to the whole PATH but the PATH does not have a defined '\0' character at the end....
Code:#include <stdio.h> #include <stdlib.h> #include <string.h> int main(void) { char *a = "SYSTEM PATH = "; char *b = getenv("PATH"); if ( b != NULL ) { char *c = malloc(strlen(a) + strlen(b) + 1); if ( c != NULL ) { strcpy(c, a); strcat(c, b); puts(c); free(c); } } return 0; }
7. It is easier to write an incorrect program than understand a correct one.
40. There are two ways to write error-free programs; only the third one works.*
thanx a lot for your reply....
however, i ran the code that you listed in a MS vc++ environment, and it gives me an error:
error C2440: 'initializing' : cannot convert from 'void *' to 'char *'
Conversion from 'void*' to pointer to non-'void' requires an explicit cast
thanks,
sameer
Compile the C code as C? If you have the file saved as .cpp, try it again as a .c file.
7. It is easier to write an incorrect program than understand a correct one.
40. There are two ways to write error-free programs; only the third one works.*
Not in C it isn't. In C++ yes. But not in C. You never need to typecast the return of malloc, and in fact you shouldn't. Search the FAQ or forum for why.
Quzah.
Hope is the first step on the road to disappointment.
