Linux编程学习——getopt_long

/* getopt_long_demo - demonstrate getopt_long() usage
*
* This application shows you one way of using getopt_long()
* to process your command-line options and store them in a
* global structure for easy access.
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>

/* doc2html supports the following command-line arguments:
*
* -I - don't produce a keyword index
* -l lang - produce output in the specified language, lang
* -o outfile - write output to outfile instead of stdout
* -v - be verbose; more -v means more diagnostics
* additional file names are used as input files
*
* In addition to the standard 'short' options, this
* version also supports these 'long' options:
*
* --no-index
* --language=lang
* --output=outfile
* --verbose
*
* The optString global tells getopt_long() which options we
* support, and which options have arguments.
*
* The longOpts global tells getopt_long() which long options
* we support, and which long options have arguments.
*/

struct globalArgs_t {
int noIndex; /* -I option */
char *langCode; /* -l option */
const char *outFileName; /* -o option */
FILE *outFile;
int verbosity; /* -v option */
char **inputFiles; /* input files */
int numInputFiles; /* # of input files */
int randomized; /* --randomize option */
} globalArgs;

static const char *optString = "Il:o:vh?";

static const struct option longOpts[] = {
{ "no-index", no_argument, NULL, 'I' },
{ "language", required_argument, NULL, 'l' },
{ "output", required_argument, NULL, 'o' },
{ "verbose", no_argument, NULL, 'v' },
{ "randomize", no_argument, NULL, 0 },
{ "help", no_argument, NULL, 'h' },
{ NULL, no_argument, NULL, 0 }
};

/* Display program usage, and exit.
*/
void display_usage( void )
{
puts( "doc2html - convert documents to HTML" );
/* ... */
exit( EXIT_FAILURE );
}

/* Convert the input files to HTML, governed by globalArgs.
*/
void convert_document( void )
{
/* ... */
printf( "no-index: %d\n", globalArgs.noIndex );
printf( "language: %s\n", globalArgs.langCode );
printf( "output: %s\n", globalArgs.outFileName );
printf( "verbosity: %d\n", globalArgs.verbosity );
printf( "randomized: %d\n", globalArgs.randomized );
}

int main( int argc, char *argv[] )
{
int opt = 0;
int longIndex = 0;

/* Initialize globalArgs before we get to work. */
globalArgs.noIndex = 0; /* false */
globalArgs.langCode = NULL;
globalArgs.outFileName = NULL;
globalArgs.outFile = NULL;
globalArgs.verbosity = 0;
globalArgs.inputFiles = NULL;
globalArgs.numInputFiles = 0;
globalArgs.randomized = 0;

/* Process the arguments with getopt_long(), then
* populate globalArgs.
*/
opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
while( opt != -1 ) {
switch( opt ) {
case 'I':
globalArgs.noIndex = 1; /* true */
break;

case 'l':
globalArgs.langCode = optarg;
break;

case 'o':
globalArgs.outFileName = optarg;
break;

case 'v':
globalArgs.verbosity++;
break;

case 'h': /* fall-through is intentional */
case '?':
display_usage();
break;

case 0: /* long option without a short arg */
/* 我还添加了 0 的 case，以便处理任何不与现有短选项匹配的长选项。
* 在此例中，只有一个长选项，但代码仍然使用 strcmp() 来确保它是预期的那个选项。
* */
if( strcmp( "randomize", longOpts[longIndex].name ) == 0 ) {
globalArgs.randomized = 1;
}
break;

default:
/* You won't actually get here. */
break;
}

opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
}

globalArgs.inputFiles = argv + optind;
globalArgs.numInputFiles = argc - optind;

convert_document();

return EXIT_SUCCESS;
}