程序代码：

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

int main(int argc,int *argv[])
{
    int ch;
    FILE *fp;
    long count=0;
    
    if(argc!=2)
    {
        printf("Usage:%s filename\n",argv[0]);
        exit(0);
    }
    if((fp=fopen(argv[1],"r"))==NULL)
    {
        printf("Can't open %s\n",argv[1]);
        exit(1);
    }
    while((ch=getc(fp))!=EOF)
    {
        putc(ch,stdout);
        count++;
    }
    fclose(fp);
    printf("File %s has %ld characters\n",argv[1],count);
    return 0;
}