how do I find the length of input in C, when the input is via shell? -

let's say, user types in

echo abc, de | ./test 

in shell (already have test.c compiled), how length of input (in case it's 7)?

count number of characters in standard input.

int main() {     int n = 0;     while (getchar() != eof) {         n++;     }     n--; // ignore final newline     printf("%d chars\n", n);     return 0; }