2.9BSD - /usr/src/cmd/rev.c

   1: #include <stdio.h>
   2: 
   3: /* reverse lines of a file */
   4: 
   5: #define N 256
   6: char line[N];
   7: FILE *input;
   8: 
   9: main(argc,argv)
  10: char **argv;
  11: {
  12:     register i,c;
  13:     input = stdin;
  14:     do {
  15:         if(argc>1) {
  16:             if((input=fopen(argv[1],"r"))==NULL) {
  17:                 fprintf(stderr,"rev: cannot open %s\n",
  18:                     argv[1]);
  19:                 exit(1);
  20:             }
  21:         }
  22:         for(;;){
  23:             for(i=0;i<N;i++) {
  24:                 line[i] = c = getc(input);
  25:                 switch(c) {
  26:                 case EOF:
  27:                     goto eof;
  28:                 default:
  29:                     continue;
  30:                 case '\n':
  31:                     break;
  32:                 }
  33:                 break;
  34:             }
  35:             while(--i>=0)
  36:                 putc(line[i],stdout);
  37:             putc('\n',stdout);
  38:         }
  39: eof:
  40:         fclose(input);
  41:         argc--;
  42:         argv++;
  43:     } while(argc>1);
  44: }

Defined functions

Defined variables

Defined macros