查看命令行提供的参数

#include <stdio.h>
int main(int argc, char *argv[])
{
    int count;
    printf("The command line has %d arguments:\n", argc);
    for(count = 0; count < argc; count++)
        printf("%d: %s\n", count, argv[count]);
    return 0;
}



一个实用的文件复制程序


#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
    FILE *fpin, *fpout;
    if( argc < 3)
    {
        printf("you must provide the source and target file.\n");
        exit(0);
    }
    if((fpin = fopen(argv[1], "r"))==NULL)
    {
        printf("the source file open fail.\n");
        exit(0);
    }
    if((fpout = fopen(argv[2], "w"))==NULL)
    {
        printf("the targe file open fail.\n");
        exit(0);
    }
    char ch;
    while((ch=getc(fpin))!=EOF)
        putc(ch, fpout);
    printf("The file is copied.\n");
    fclose(fpout);
    fclose(fpin);
    return 0;
}