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copied!<p>Ok, so let's walk through some of the lines in parse args</p> <pre><code>wbuf=buffer; buf_args[0]=buffer; args[0] =buffer; </code></pre> <p>This sets <code>wbuf</code> to point to what is in the <code>buffer</code>. It also sets the first pointer in the array of <code>buf_args</code> to the <code>buffer</code>. And it does the same thing for the first element of <code>args</code> as well. </p> <pre><code>for(cp=buf_args; (*cp=strsep(&wbuf, " \n\t")) != NULL ;){ if ((*cp != '\0') && (++cp >= &buf_args[args_size])) break; } </code></pre> <p>The function <code>strsep</code> looks through <code>wbuf</code> for the delimiters space, newline or tab and returns a pointer to the begining of a token, with <code>wbuf</code> updated to the end of the token. If there are no more delimiters in the string, the function returns <code>NULL</code>. So, the middle part of the <code>for</code> statement continues until <code>*cp</code> equals <code>NULL</code>. </p> <p>So, the pointer <code>cp</code> initially points to the string (pointer) in <code>buf_args[0]</code>. The string separator function fills <code>*cp</code> with the address of the token. Then, the <code>if</code> statement check 1) if the <code>for</code> loop has exceeded the capacity of <code>buf_args</code>, by checking whether the pointer <code>cp</code> has exceeded the last element and 2) if the first character of the returned token is the end of string character.</p> <p>Note: I think that line should be <code>*(*cp) != '\0'</code>?</p> <pre><code>for (j=i=0; buf_args[i]!=NULL; i++){ if(strlen(buf_args[i])>0) args[j++]=buf_args[i]; } </code></pre> <p>Then, it loops over all the <code>buf_args</code> until it finds a <code>NULL</code> one. If the string pointed to by <code>buf_args</code> is longer than 0, i.e. it has characters, the array <code>args</code> gets a copy of the pointer to the token.</p> <pre><code>*nargs=j; args[j]=NULL; </code></pre> <p>The last element of <code>args</code> after the filled entries is set to <code>NULL</code>. And the value of <code>nargs</code> is set to the length of the number of filled elements in the <code>args</code> array.</p>

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