linux 中解析命令行参数 （getopt_long用法)

/*
*以下部分的结果处理和各种变更的定义都省略了，我们只关心与命令行处理相关的东西。
*/
.............

static struct option long_options[] = {
{"help",				no_argument, 0, 'h'},
{"version",				no_argument, 0, 'e'},
{"default-vendor",		required_argument, 0, 'v'},
{"default-product",		required_argument, 0, 'p'},
{"target-vendor",		required_argument, 0, 'V'},
{"target-product",		required_argument, 0, 'P'},
{"target-class",		required_argument, 0, 'C'},
{"message-endpoint",	required_argument, 0, 'm'},
{"message-content",		required_argument, 0, 'M'},
{"response-endpoint",	required_argument, 0, 'r'},
{"detach-only",			no_argument, 0, 'd'},
{"huawei-mode",			no_argument, 0, 'H'},
{"sierra-mode",			no_argument, 0, 'S'},
{"sony-mode",			no_argument, 0, 'O'},
{"gct-mode",			no_argument, 0, 'G'},
{"need-response",		no_argument, 0, 'n'},
{"reset-usb",			no_argument, 0, 'R'},
{"config",				required_argument, 0, 'c'},
{"verbose",				no_argument, 0, 'W'},
{"quiet",				no_argument, 0, 'Q'},
{"no-inquire",			no_argument, 0, 'I'},
{"check-success",		required_argument, 0, 's'},
{"interface",			required_argument, 0, 'i'},
{"configuration",		required_argument, 0, 'u'},
{"altsetting",			required_argument, 0, 'a'},
{0, 0, 0, 0}
};

...................

int readArguments(int argc, char **argv)
{
int c, option_index = 0, count=0;
if(argc==1) return 0;

while (1)
{
c = getopt_long (argc, argv, "heWQndHSOGRIv:p:V:P:C:m:M:r:c:i:u:a:s:",
long_options, &option_index);

/* Detect the end of the options. */
if (c == -1)
break;
count++;
switch (c)
{
case 'R': ResetUSB = 1; break;
case 'v': DefaultVendor = strtol(optarg, NULL, 16); break;
case 'p': DefaultProduct = strtol(optarg, NULL, 16); break;
case 'V': TargetVendor = strtol(optarg, NULL, 16); break;
case 'P': TargetProduct = strtol(optarg, NULL, 16); break;
case 'C': TargetClass = strtol(optarg, NULL, 16); break;
case 'm': MessageEndpoint = strtol(optarg, NULL, 16); break;
case 'M': strcpy(MessageContent, optarg); break;
case 'n': NeedResponse = 1; break;
case 'r': ResponseEndpoint = strtol(optarg, NULL, 16); break;
case 'd': DetachStorageOnly = 1; break;
case 'H': HuaweiMode = 1; break;
case 'S': SierraMode = 1; break;
case 'O': SonyMode = 1; break;
case 'G': GCTMode = 1; break;
case 'c': readConfigFile(optarg); break;
case 'W': verbose = 1; show_progress = 1; count--; break;
case 'Q': show_progress = 0; verbose = 0; count--; break;
case 's': CheckSuccess = strtol(optarg, NULL, 16); count--; break;
case 'I': InquireDevice = 0; break;

case 'i': Interface = strtol(optarg, NULL, 16); break;
case 'u': Configuration = strtol(optarg, NULL, 16); break;
case 'a': AltSetting = strtol(optarg, NULL, 16); break;

case 'e':
printVersion();
exit(0);
break;
case 'h':
printVersion();
printf ("Usage: usb_modeswitch [-hvpVPmMrdHn] [-c filename]/n/n");
printf (" -h, --help                    this help/n");
printf (" -e, --version                 print version number and exit/n");
printf (" -v, --default-vendor [nr]     vendor ID to look for (mandatory)/n");
printf (" -p, --default-product [nr]    product ID to look for (mandatory)/n");
printf (" -V, --target-vendor [nr]      target vendor (optional, for success check)/n");
printf (" -P, --target-product [nr]     target model (optional, for success check)/n");
printf (" -C, --target-class [nr]       target device class/n");
printf (" -m, --message-endpoint [nr]   where to direct the message (optional)/n");
printf (" -M, --message-content [str]   command to send (hex number as string)/n");
printf (" -n, --need-response           read a response to the message transfer/n");
printf (" -r, --response-endpoint [nr]  where from read the response (optional)/n");
printf (" -d, --detach-only             just detach the storage driver/n");
printf (" -H, --huawei-mode             apply a special procedure/n");
printf (" -S, --sierra-mode             apply a special procedure/n");
printf (" -O, --sony-mode               apply a special procedure/n");
printf (" -G, --gct-mode                apply a special procedure/n");
printf (" -R, --reset-usb               reset the device in the end/n");
printf (" -c, --config [filename]       load different config file/n");
printf (" -Q, --quiet                   don't show progress or error messages/n");
printf (" -W, --verbose                 print all settings before running/n");
printf (" -s, --success [nr]            check switching result after [nr] secs/n");
printf (" -I, --no-inquire              do not get device details (default on)/n/n");
printf (" -i, --interface [nr]          select initial USB interface (default 0)/n");
printf (" -u, --configuration [nr]      select USB configuration/n");
printf (" -a, --altsetting [nr]         select alternative USB interface setting/n/n");
exit(0);
break;

default: //Unsupported - error message has already been printed
printf ("/n");
exit(1);
}
}

return count;
}

int main(int argc, char **argv)
{

.......................

// Check command arguments, use params instead of config file when given
switch (readArguments(argc, argv)) {
case 0:						// no argument or -W, -q or -s
readConfigFile("/etc/usb_modeswitch.conf");//这里的读取配置文件，将是下一篇文章讲的
break;
default:					// one or more arguments except -W, -q or -s
if (!config_read)		// if arguments contain -c, the config file was already processed
if (verbose) printf("Taking all parameters from the command line/n/n");
}
.......................
processing...
/*
*	根据readArguments函数中变局变量的结果，进行相应的处理。
*/
.......................
}