LXR toybox/toys/pending/more.c

   1/* more.c - View FILE (or stdin) one screenful at a time.
   2 *
   3 * Copyright 2013 Bilal Qureshi <bilal.jmi@gmail.com>
   4 *
   5 * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/more.html
   6
   7USE_MORE(NEWTOY(more, 0, TOYFLAG_USR|TOYFLAG_BIN))
   8
   9config MORE
  10  bool "more"
  11  default n
  12  help
  13    usage: more [FILE...]
  14
  15    View FILE(s) (or stdin) one screenful at a time.
  16*/
  17
  18#define FOR_more
  19#include "toys.h"
  20
  21GLOBALS(
  22  struct termios inf;
  23  int cin_fd;
  24)
  25
  26static void signal_handler(int sig)
  27{
  28  // Reset the terminal whether we were signalled or exited normally.
  29  tcsetattr(TT.cin_fd, TCSANOW, &TT.inf);
  30
  31  if (sig == 0) _exit(0);
  32
  33  // We were actually signalled, so move to a new line and re-raise the signal.
  34  xputc('\n');
  35  signal(sig, SIG_DFL);
  36  raise(sig);
  37  _exit(sig | 128);
  38}
  39
  40static void show_file_header(const char *name)
  41{
  42  printf(":::::::::::::::::::::::\n%s\n:::::::::::::::::::::::\n", name);
  43}
  44
  45static int prompt(FILE *cin, const char* fmt, ...)
  46{
  47  int input_key;
  48  va_list ap;
  49
  50  printf("\33[7m"); // Reverse video before printing the prompt.
  51
  52  va_start(ap, fmt);
  53  vfprintf(stdout, fmt, ap);
  54  va_end(ap);
  55
  56  while (1) {
  57    fflush(NULL);
  58    input_key = tolower(getc(cin));
  59    printf("\33[0m\33[1K\r"); // Reset all attributes, erase to start of line.
  60    if (strchr(" \nrq", input_key)) {
  61      fflush(NULL);
  62      return input_key;
  63    }
  64    printf("\33[7m(Enter:Next line Space:Next page Q:Quit R:Show the rest)");
  65  }
  66}
  67
  68static void do_cat_operation(int fd, char *name)
  69{
  70  if (toys.optc > 1) show_file_header(name);
  71  xsendfile(fd, 1);
  72}
  73
  74void more_main()
  75{
  76  int ch, input_key = 0, show_prompt;
  77  unsigned rows = 24, cols = 80, row = 0, col = 0;
  78  struct stat st;  
  79  struct termios newf;
  80  FILE *fp, *cin;
  81
  82  if (!isatty(1) || !(cin = fopen("/dev/tty", "r"))) {
  83    loopfiles(toys.optargs, do_cat_operation);
  84    return;
  85  }
  86
  87  TT.cin_fd = fileno(cin);
  88  tcgetattr(TT.cin_fd, &TT.inf);
  89
  90  //Prepare terminal for input
  91  memcpy(&newf, &TT.inf, sizeof(struct termios));
  92  newf.c_lflag &= ~(ICANON | ECHO);
  93  newf.c_cc[VMIN] = 1;
  94  newf.c_cc[VTIME] = 0;
  95  tcsetattr(TT.cin_fd, TCSANOW, &newf);
  96
  97  sigatexit(signal_handler);
  98
  99  do {
 100    fp = stdin;
 101    if (*toys.optargs && !(fp = fopen(*toys.optargs, "r"))) {
 102        perror_msg("%s", *toys.optargs);
 103        goto next_file;
 104    }
 105    st.st_size = show_prompt = col = row = 0;
 106    fstat(fileno(fp), &st);
 107    terminal_size(&cols, &rows);
 108    rows--;
 109
 110    if (toys.optc > 1) {
 111      show_file_header(*toys.optargs);
 112      row += 3;
 113    }
 114
 115    while ((ch = getc(fp)) != EOF) {
 116      if (input_key != 'r' && show_prompt) {
 117        if (st.st_size)
 118          input_key = prompt(cin, "--More--(%d%% of %lld bytes)",
 119              (int) (100 * ( (double) ftell(fp) / (double) st.st_size)),
 120              (long long)st.st_size);
 121        else
 122          input_key = prompt(cin, "--More--");
 123        if (input_key == 'q') goto stop; 
 124
 125        col = row = show_prompt = 0;
 126        terminal_size(&cols, &rows);
 127        rows--;
 128      }
 129
 130      putchar(ch);
 131      if (ch == '\t') col = (col | 0x7) + 1;
 132      else col++;
 133      if (col == cols) putchar(ch = '\n');
 134      if (ch == '\n') {
 135        col = 0;
 136        if (++row >= rows || input_key == '\n') show_prompt = 1;
 137      }
 138    }
 139    fclose(fp);
 140
 141next_file:
 142    if (*toys.optargs && *++toys.optargs) {
 143      input_key = prompt(cin, "--More--(Next file: %s)", *toys.optargs);
 144      if (input_key == 'q') goto stop;
 145    }
 146  } while (*toys.optargs);
 147
 148stop:
 149  tcsetattr(TT.cin_fd, TCSANOW, &TT.inf);
 150  fclose(cin);
 151  // Even if optarg not found, exit value still 0
 152  toys.exitval = 0;
 153}
 154