lalstar2002

麻煩各各大大能稍做解釋
讓不是對C很了解的我
能明白大概每行的指令在做什麼事情
以下是程式碼

#include <stdio.h>
#define BUFFERSIZE 1024
int main(int argc, char **argv) {
  char *src, *dest;
  FILE *s, *d;
  char buffer[BUFFERSIZE];
  
  if (argc>1) src = argv[1];
  else { fprintf(stderr,"%s: no input file name",argv[0]); exit(1); }
  if (argc>2) dest = argv[2];
  else { fprintf(stderr,"%s: no output file name",argv[0]); exit(2); }
  if ((s = fopen(src,"r"))==NULL) {
    fprintf(stderr,"%s: can't open input file %s",argv[0],src); exit(3);
  }
  if ((d = fopen(dest,"w"))==NULL) {
    fprintf(stderr,"%s: can't open output file %s",argv[0],dest); exit(4);
  }
  while (!feof(s)) {
    if (fgets(buffer,BUFFERSIZE,s)) {
      fputs(buffer,d);
    }
  }
  fclose(s); fclose(d);
  exit(0);
}