getopt test

试了一下getopt，代码如下：

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

int main(int argc, char** argv) {
    int c;
    char * filename = NULL;
    char * input_path = NULL;
    char * output_path = NULL;
    bool each_by_line = false;
    while((c=getopt(argc,argv,"lf:i:o:")) != -1){
        switch(c){
            case 'f':
                filename = optarg;
                break;
            case 'i':
                input_path = optarg;
                break;
            case 'o':
                output_path = optarg;
                break;
            case 'l':
                each_by_line = true;
        }
    }
	
	if(each_by_line){
		printf("process one line each time\n");
	}else if(filename != NULL){
		if(input_path == NULL || output_path == NULL){
			fprintf(stderr,"if filename is set, the input_path and output_path should be set,too\n");
			exit(1);
		}
		printf("process one file each time\n");
		printf("filename:%s,input_path:%s,output_path:%s\n",filename,input_path,output_path);
	}else{
		printf("process by default\n");
	}
	return 0;
}