xref: /third_party/toybox/toys/pending/more.c (revision 0f66f451) 
1/* more.c - View FILE (or stdin) one screenfull 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 screenfull 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 we were actually signalled, move to a new line and re-raise the signal.
32  if (sig != 0) {
33    xputc('\n');
34    signal(sig, SIG_DFL);
35    raise(sig);
36    _exit(sig | 128);
37  }
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 int more_directory(char *path, struct stat *st)
69{
70  if (!stat(path, st) && S_ISDIR(st->st_mode)) {
71    printf("\n*** %s: directory ***\n\n", path);
72    return 1;
73  }
74  return 0;
75}
76
77static void do_cat_operation(int fd, char *name)
78{
79  struct stat st;
80
81  if (!more_directory(name, &st)) {
82    show_file_header(name);
83    fflush(stdout);
84    xsendfile(fd, 1);
85  }
86}
87
88void more_main()
89{
90  int ch, input_key = 0, show_prompt;
91  unsigned rows = 24, cols = 80, row = 0, col = 0;
92  struct stat st;
93  struct termios newf;
94  FILE *fp, *cin;
95
96  if (!isatty(1) || !(cin = fopen("/dev/tty", "r"))) {
97    loopfiles(toys.optargs, do_cat_operation);
98    return;
99  }
100
101  TT.cin_fd = fileno(cin);
102  tcgetattr(TT.cin_fd, &TT.inf);
103
104  //Prepare terminal for input
105  memcpy(&newf, &TT.inf, sizeof(struct termios));
106  newf.c_lflag &= ~(ICANON | ECHO);
107  newf.c_cc[VMIN] = 1;
108  newf.c_cc[VTIME] = 0;
109  tcsetattr(TT.cin_fd, TCSANOW, &newf);
110
111  sigatexit(signal_handler);
112
113  do {
114    char *filename = *toys.optargs;
115
116    st.st_size = show_prompt = col = row = 0;
117    if (!filename) fp = stdin;
118    else {
119      if (more_directory(filename, &st)) goto next_file;
120      if (!(fp = fopen(filename, "r"))) {
121        perror_msg("%s", filename);
122        goto next_file;
123      }
124    }
125
126    terminal_size(&cols, &rows);
127    rows--;
128
129    if (toys.optc > 1) {
130      show_file_header(filename);
131      row += 3;
132    }
133
134    while ((ch = getc(fp)) != EOF) {
135      if (input_key != 'r' && show_prompt) {
136        if (st.st_size)
137          input_key = prompt(cin, "--More--(%d%% of %lld bytes)",
138              (int) (100 * ( (double) ftell(fp) / (double) st.st_size)),
139              (long long)st.st_size);
140        else
141          input_key = prompt(cin, "--More--");
142        if (input_key == 'q') goto stop;
143
144        col = row = show_prompt = 0;
145        terminal_size(&cols, &rows);
146        rows--;
147      }
148
149      putchar(ch);
150      if (ch == '\t') col = (col | 0x7) + 1;
151      else col++;
152      if (col == cols) putchar(ch = '\n');
153      if (ch == '\n') {
154        col = 0;
155        if (++row >= rows || input_key == '\n') show_prompt = 1;
156      }
157    }
158    fclose(fp);
159
160next_file:
161    if (*toys.optargs && *++toys.optargs) {
162      input_key = prompt(cin, "--More--(Next file: %s)", *toys.optargs);
163      if (input_key == 'q') goto stop;
164    }
165  } while (*toys.optargs);
166
167stop:
168  tcsetattr(TT.cin_fd, TCSANOW, &TT.inf);
169  fclose(cin);
170  // Even if optarg not found, exit value still 0
171  toys.exitval = 0;
172}
173