| 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 | } |