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-rw-r--r--read-quickly.c482
1 files changed, 482 insertions, 0 deletions
diff --git a/read-quickly.c b/read-quickly.c
new file mode 100644
index 0000000..acd52a6
--- /dev/null
+++ b/read-quickly.c
@@ -0,0 +1,482 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <termios.h>
+#include <unistd.h>
+#include <wchar.h>
+
+
+
+/**
+ * The default word rate.
+ */
+#ifndef DEFAULT_RATE
+# define DEFAULT_RATE 120 /* 2 hz */
+#endif
+
+/**
+ * Delta-value of rate increment and rate decrement.
+ */
+#ifndef RATE_DELTA
+# define RATE_DELTA 10 /* 10/min */
+#endif
+
+
+
+/**
+ * The a word.
+ */
+struct word {
+ /**
+ * The word.
+ */
+ const char *word;
+
+ /**
+ * Should reverse video be applied?
+ */
+ int reverse_video;
+};
+
+/**
+ * The name of the process.
+ */
+static const char *argv0;
+
+/**
+ * Have the terminal been resized?
+ */
+static volatile sig_atomic_t caught_sigwinch = 1;
+
+/**
+ * Has the timer expired?
+ */
+static volatile sig_atomic_t caught_sigalrm = 0;
+
+/**
+ * The width of the terminal.
+ */
+static size_t width = 80;
+
+/**
+ * The height of the terminal.
+ */
+static size_t height = 30;
+
+/**
+ * The number of words.
+ */
+static size_t word_count = 0;
+
+/**
+ * All loaded words. Refer to `word_count`
+ * for the number of contained words.
+ */
+static struct word *words;
+
+
+
+/**
+ * Signal handler for SIGWINCH.
+ * Invoked when the terminal resizes.
+ */
+static void
+sigwinch(int signo)
+{
+ caught_sigwinch = 1;
+ (void) signo;
+}
+
+
+/**
+ * Signal handler for SIGALRM.
+ * Invoked when the timer expires.
+ */
+static void
+sigalrm(int signo)
+{
+ caught_sigalrm = 1;
+ (void) signo;
+}
+
+
+/**
+ * Get the size of the terminal.
+ */
+static void
+get_terminal_size(void)
+{
+ struct winsize winsize;
+ if (caught_sigwinch) {
+ caught_sigwinch = 0;
+ while (ioctl(STDOUT_FILENO, (unsigned long)TIOCGWINSZ, &winsize) < 0)
+ if (errno != EINTR)
+ return;
+ height = winsize.ws_row;
+ width = winsize.ws_col;
+ }
+}
+
+
+/**
+ * Get the selected word rate by reading
+ * the environment variable READ_QUICKLY_RATE.
+ *
+ * @return The rate in words per minute.
+ */
+static long
+get_word_rate(void)
+{
+ char *s;
+ long r;
+
+ errno = 0;
+ s = getenv("READ_QUICKLY_RATE");
+ if (!s || !*s || !isdigit(*s))
+ return DEFAULT_RATE;
+
+ r = strtol(s, &s, 10);
+ if (r <= 0)
+ return DEFAULT_RATE;
+ while (*s == ' ')
+ s++;
+
+ if (!*s) r *= 1;
+ else if (!strcasecmp(s, "wpm")) r *= 1;
+ else if (!strcasecmp(s, "w/m")) r *= 1;
+ else if (!strcasecmp(s, "/m")) r *= 1;
+ else if (!strcasecmp(s, "wpmin")) r *= 1;
+ else if (!strcasecmp(s, "w/min")) r *= 1;
+ else if (!strcasecmp(s, "/min")) r *= 1;
+ else if (!strcasecmp(s, "wps")) r *= 60;
+ else if (!strcasecmp(s, "w/s")) r *= 60;
+ else if (!strcasecmp(s, "/s")) r *= 60;
+ else if (!strcasecmp(s, "wpsec")) r *= 60;
+ else if (!strcasecmp(s, "w/sec")) r *= 60;
+ else if (!strcasecmp(s, "/sec")) r *= 60;
+ else if (!strcasecmp(s, "hz")) r *= 60;
+ else
+ return DEFAULT_RATE;
+
+ return r;
+}
+
+
+/**
+ * Count the number of character in a string.
+ *
+ * @param s The string.
+ * @return The number of characters in `s`.
+ */
+static size_t
+display_len(const char *s)
+{
+ size_t r = 0;
+ wchar_t wc;
+ int len, w;
+ for (; *s; s += len) {
+ len = mbtowc(&wc, s, SIZE_MAX);
+ if (len <= 0)
+ break;
+ w = wcwidth(wc);
+ if (w < 0)
+ break;
+ r += (size_t)w;
+ }
+ return r;
+}
+
+
+/**
+ * Load the file and do some preparsing.
+ *
+ * @param fd The file descriptor to the file, -1 to clean up instead.
+ * @return 0 on success, -1 on error.
+ */
+static int
+load_file(int fd)
+{
+ static char *buffer = NULL;
+ size_t ptr = 0;
+ size_t size = 0;
+ void *new;
+ int saved_errno;
+ char *s;
+ char *end;
+ size_t i;
+ ssize_t n;
+
+ if (fd == -1)
+ return free(buffer), 0;
+
+ /* Load file. */
+ for (;;) {
+ if (ptr == size) {
+ size = size ? size << 1 : 8 << 10;
+ new = realloc(buffer, size);
+ if (!new)
+ goto fail;
+ buffer = new;
+ }
+ n = read(fd, buffer + ptr, size - ptr);
+ if (n <= 0) {
+ if (!n)
+ break;
+ if (errno == EINTR)
+ continue;
+ goto fail;
+ }
+ ptr += (size_t)n;
+ }
+ if (!buffer)
+ return 0;
+ new = realloc(buffer, ptr + 2);
+ if (!new)
+ goto fail;
+ buffer = new;
+ buffer[ptr++] = '\0';
+ buffer[ptr++] = '\0';
+
+ /* Split words. */
+ size = 0;
+ for (s = buffer; *s; s = &end[1]) {
+ if (word_count == size) {
+ size = size ? size << 1 : 512;
+ new = realloc(words, size * sizeof(*words));
+ if (!new)
+ goto fail;
+ words = new;
+ }
+ while (isspace(*s))
+ s++;
+ end = strpbrk(s, " \f\n\r\t\v");
+ if (!end)
+ end = strchr(s, '\0');
+ *end = '\0';
+ words[word_count].word = s;
+ words[word_count].reverse_video = 0;
+ word_count++;
+ }
+
+ /* Figure out which words should have reverse video. */
+ for (i = 1; i < word_count; i++)
+ if (!strcmp(words[i].word, words[i - 1].word))
+ words[i].reverse_video = words[i - 1].reverse_video ^ 1;
+
+ return 0;
+
+fail:
+ saved_errno = errno;
+ free(buffer);
+ buffer = NULL;
+ errno = saved_errno;
+ return -1;
+}
+
+
+/**
+ * Display a file word by word.
+ *
+ * @param ttyfd File descriptor for reading from the terminal.
+ * @param rate The number of words per minute to display.
+ * @return 0 on success, -1 on error.
+ */
+static int
+display_file(int ttyfd, long rate)
+{
+#define SET_RATE \
+ (interval.it_value.tv_usec = 60000000L / rate, \
+ interval.it_value.tv_sec = interval.it_value.tv_usec / 1000000L, \
+ interval.it_value.tv_usec %= 1000000L)
+
+ ssize_t n;
+ int timer_set = 1;
+ char c;
+ size_t i;
+ struct itimerval interval;
+
+ memset(&interval, 0, sizeof(interval));
+
+ SET_RATE;
+ for (i = 0; i < word_count; i++) {
+ if (setitimer(ITIMER_REAL, &interval, NULL))
+ goto fail;
+ rewait:
+ n = read(ttyfd, &c, sizeof(c));
+ if (n < 0) {
+ if (errno != EINTR)
+ goto fail;
+ c = 0;
+ } else if (n == 0) {
+ break;
+ }
+ switch (c) {
+ case '+': /* plus */
+ case '-': /* hyphen */
+ rate += c == '+' ? RATE_DELTA : -RATE_DELTA;
+ rate = rate <= 0 ? 1 : rate;
+ SET_RATE;
+ goto rewait;
+ case 'p': /* P */
+ if (timer_set)
+ memset(&interval, 0, sizeof(interval));
+ else
+ SET_RATE;
+ if (setitimer(ITIMER_REAL, &interval, NULL))
+ goto fail;
+ timer_set ^= 1;
+ goto rewait;
+ case 'q': /* Q */
+ goto done;
+ case 'B': /* down */
+ case 'C': /* right */
+ break;
+ case 'A': /* up */
+ case 'D': /* left */
+ i = i < 2 ? 0 : i - 2;
+ break;
+ case 0:
+ if (!caught_sigalrm)
+ goto rewait;
+ caught_sigalrm = 0;
+ break;
+ default:
+ goto rewait;
+ }
+
+ get_terminal_size();
+ if (fprintf(stdout, "\033[H\033[2J\033[%zu;%zuH%s%s%s",
+ (height + 1) / 2,
+ (width - display_len(words[i].word)) / 2 + 1,
+ words[i].reverse_video ? "\033[7m" : "",
+ words[i].word,
+ words[i].reverse_video ? "\033[27m" : "") < 0)
+ goto fail;
+ if (fflush(stdout))
+ goto fail;
+ }
+
+ if (setitimer(ITIMER_REAL, &interval, NULL))
+ goto fail;
+ (void) read(ttyfd, &c, sizeof(c));
+
+done:
+ return 0;
+
+fail:
+ return -1;
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ long rate = get_word_rate();
+ int fd = -1, ttyfd = -1, tty_configured = 0;
+ struct termios stty, saved_stty;
+ struct stat _attr;
+ struct sigaction sa;
+
+ /* Parse arguments. */
+ argv0 = argv ? (argc--, *argv++) : "read-quickly";
+ if (argc && argv[0][0] == '-') {
+ if (argv[0][1] == '-' && !argv[0][2]) {
+ argc--;
+ argv++;
+ } else if (argv[0][1]) {
+ goto usage;
+ }
+ }
+ if (argc > 1)
+ goto usage;
+
+ /* Check that we have a stdout. */
+ if (fstat(STDOUT_FILENO, &_attr))
+ if (errno == EBADF)
+ goto fail;
+
+ /* Open file. */
+ if (argc && strcmp(*argv, "-")) {
+ fd = open(*argv, O_RDONLY);
+ if (fd < 0)
+ goto fail;
+ } else {
+ fd = STDIN_FILENO;
+ }
+
+ /* Load file. */
+ if (load_file(fd))
+ goto fail;
+
+ /* We do not need the file anymore. */
+ close(fd);
+ fd = -1;
+
+ /* Get a readable file descriptor for the controlling terminal. */
+ ttyfd = open("/dev/tty", O_RDONLY);
+ if (ttyfd < 0)
+ goto fail;
+
+ /* Configure terminal. */
+ if (fprintf(stdout, "\033[?1049h\033[?25l") < 0)
+ goto fail;
+ if (fflush(stdout))
+ goto fail;
+ if (tcgetattr(ttyfd, &stty))
+ goto fail;
+ saved_stty = stty;
+ stty.c_lflag &= (tcflag_t)~(ICANON | ECHO | ISIG);
+ if (tcsetattr(ttyfd, TCSAFLUSH, &stty))
+ goto fail;
+ tty_configured = 1;
+
+ /* Display file. */
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = sigalrm;
+ sigaction(SIGALRM, &sa, NULL);
+ sa.sa_handler = sigwinch;
+ sigaction(SIGWINCH, &sa, NULL);
+ if (display_file(ttyfd, rate))
+ goto fail;
+
+ /* Restore terminal configurations. */
+ tcsetattr(ttyfd, TCSAFLUSH, &saved_stty);
+ fprintf(stdout, "\033[?25h\033[?1049l");
+ fflush(stdout);
+ tty_configured = 0;
+
+ free(words);
+ load_file(-1);
+ close(ttyfd);
+ return 0;
+
+fail:
+ perror(argv0);
+ free(words);
+ load_file(-1);
+ if (tty_configured) {
+ tcsetattr(ttyfd, TCSAFLUSH, &saved_stty);
+ fprintf(stdout, "\033[?25h\033[?1049l");
+ fflush(stdout);
+ }
+ if (fd >= 0)
+ close(fd);
+ if (ttyfd >= 0)
+ close(ttyfd);
+ return 1;
+
+usage:
+ fprintf(stderr, "usage: %s [file].\n", argv0);
+ return 1;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-08 14:17:33 +0000