Princeton University
COS 217: Introduction to Pgmming Systems

Purpose

Describe how command line arguments are passed (from the shell) into your C program

Arrays of Strings

We've seen arrays, and strings as a special case of arrays

So it's a logical next step to combine them: array of strings

An array, each of whose elements is a character pointer

char *a[10];
a[0] = "hello";
...

Command Line Arguments

Example: printargv.c and Trace of printargv

Illustrates an array of strings

Also illustrates how operating system passes command-line arguments to a C program

Note:

As formal parameters, these are identical:

char a[]
char *a

So, as formal parameters, these are identical:

char *argv[]
char **argv

Some C programmers prefer the latter form

Copyright © 2008 by Robert M. Dondero, Jr.