C语言argv[]与argc各有什么作用

argc与argv[]是启动C程序时系统传入的，可以直接使用。argc是参数数量，argv是参数表数组。如命令行为“prg.exe 1 2 3”，则argc为4，argv[0]="prg.exe",argv[1]="1",argv[2]="2",argv[3]="3"。以下是LCC-WIN32模板文件（加了一行显示所有参数语句）：
/* --- The following code comes from e:\lcc\lib\wizard\textmode.tpl. */
#include
#include
#include
void Usage(char *programName)
{
fprintf(stderr,"%s usage:\n",programName);
/* Modify here to add your usage message when the program is
* called without arguments */
}

/* returns the index of the first argument that is not an option; i.e.
does not start with a dash or a slash
*/
int HandleOptions(int argc,char *argv[])
{
int i,firstnonoption=0;

for (i=1; i< argc;i++) {
if (argv[i][0] == '/' || argv[i][0] == '-') {
switch (argv[i][1]) {
/* An argument -? means help is requested */
case '?':
Usage(argv[0]);
break;
case 'h':
case 'H':
if (!stricmp(argv[i]+1,"help")) {
Usage(argv[0]);
break;
}
/* If the option -h means anything else
* in your application add code here
* Note: this falls through to the default
* to print an "unknow option" message
*/
/* add your option switches here */
default:
fprintf(stderr,"unknown option %s\n",argv[i]);
break;
}
}
else {
firstnonoption = i;
break;
}
}
return firstnonoption;
}

int main(int argc,char *argv[])
{
if (argc == 1) {
/* If no arguments we call the Usage routine and exit */
Usage(argv[0]);
return 1;
}
/* handle the program options */
HandleOptions(argc,argv);
/* The code of your application goes here */

for (int i=0;i
return 0;
}