C char* array allocation - c

Question

I was writing a function to parse command line as char* arguments array to another program but then I faced a problem allocating and/or reading the resulting buffer. I am stuck on that for about 2 days and 1000+ google searches later and I just can't figure it out all by myself.
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h> //for malloc, realloc
char** parse_cmdline(const char* cmdline) {
int wrdc = 0; //word count
int wrd_len = 0; //current word length
char** args = NULL; //result buffer, filled with arguments
int i; //counter of characters read from cmdline
for(i = 0; ; ++i){
if(cmdline[i] == '\n') {
if(wrd_len > 0) {
++wrdc;
args = realloc(args, wrdc * sizeof(char*));
memcpy((void*)&args[wrdc - 1], (void*) &cmdline[i - wrd_len], wrd_len);
printf("EOL found\n");
wrd_len = 0;
}
break;
}
else if(cmdline[i] == ' ') {
if(wrd_len > 0) {
++wrdc;
args = realloc(args, wrdc * sizeof(char*));
memcpy((void*)&args[wrdc - 1], (void*) &cmdline[i - wrd_len], wrd_len);
printf("space found!\n");
wrd_len = 0;
}
}
else if(cmdline[i] > 32 && cmdline[i] < 127) {
++wrd_len;
printf("char found !\n");
}
//FOR DEBUGGING
printf("i = %d, wrdc = %d, wrd_len = %d\n", i, wrdc, wrd_len);
}
printf("%d words in command\n", wrdc);
return args;
}
int main(int argc, char* argv[]) {
char buffer[200];
while(read(STDIN_FILENO, buffer, 200) > 0) {
char** data = parse_cmdline(buffer);
printf("%s\n", data[0]);
memset(buffer, 0, 200);
free(data);
}
return 0;
}

Answer 1

else if(cmdline[i] == ' ') {
if(wrd_len > 0) {
++wrdc;
args = realloc(args, wrdc * sizeof(char*));
memcpy((void*)&args[wrdc - 1], (void*) &cmdline[i - wrd_len], wrd_len);
printf("space found!\n");
wrd_len = 0;
}
}
Here the pointer stored in args[wrdc-1] is uninitialized and pointed to somewhere unknown. You shouldn't just memcpy() the cmdline into args[wrdc-1].
Allocate the memory for one single argument before memcpy():
args[wrdc-1] = calloc(wrd_len+1, sizeof(char));
Note the +1 and calloc() for terminating NULL character. Remember to free them in main().