lchat

commit 98fa5e3861a515b0b9f7b212e7eb5abf550e1f33
parent b1db0ac6e9850a858120ac43596405208a3fc581
Author: Jan Klemkow <j.klemkow@wemelug.de>
Date:   Mon, 26 Oct 2015 22:17:57 +0100

wip

Diffstat:
M
lchat.c
 | 
174
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
M
slackline.c
 | 
58
++++++++++++++++++++++++++++++++++++++++++++++++++++------
M
slackline.h
 | 
16
+++++++---------

3 files changed, 216 insertions(+), 32 deletions(-)
diff --git a/lchat.c b/lchat.c
@@ -1,6 +1,10 @@
 #include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <term.h>
 #include <termios.h>
 #include <unistd.h>
@@ -9,29 +13,104 @@
 
 struct termios origin_term;
 
-void
+static void
 exit_handler(void)
 {
 	if (tcsetattr(STDIN_FILENO, TCSANOW, &origin_term) == -1)
 		err(EXIT_FAILURE, "tcsetattr");
 }
 
+static void
+line_output(struct slackline *sl, char *file)
+{
+	int fd;
+
+	if ((fd = open(file, O_WRONLY|O_APPEND)) == -1)
+		err(EXIT_FAILURE, "open: %s", file);
+
+	/* replace NUL-terminator with newline as line separator for file */
+	sl->buf[sl->len] = '\n';
+
+	if (write(fd, sl->buf, sl->len + 1) == -1)
+		err(EXIT_FAILURE, "write");
+
+	if (close(fd) == -1)
+		err(EXIT_FAILURE, "close");
+}
+
+static void
+usage(void)
+{
+	fprintf(stderr, "lchar [-nH] [-p prompt] [-i in] [-o out] [directory]\n");
+	exit(EXIT_FAILURE);
+}
+
 int
-main(void)
+main(int argc, char *argv[])
 {
+	char tail_cmd[BUFSIZ];
+	struct pollfd pfd[2];
 	struct termios term;
 	struct slackline *sl = sl_init();
-	char *term_name = getenv("TERM");
 	int fd = STDIN_FILENO;
 	int c;
+	int ch;
+	bool empty_line = true;
+	size_t history_len = 0;
+	char *prompt = ">";
+	size_t prompt_len = strlen(prompt);
+	char *dir = ".";
+	char *in_file = NULL;
+	char *out_file = NULL;
+	FILE *tail_fh;
+
+	while ((ch = getopt(argc, argv, "H:i:no:p:h")) != -1) {
+		switch (ch) {
+		case 'H':
+			errno = 0;
+			history_len = strtoull(optarg, NULL, 0);
+			if (errno != 0)
+				err(EXIT_FAILURE, "strtoull");
+			break;
+		case 'i':
+			if ((in_file = strdup(optarg)) == NULL)
+				err(EXIT_FAILURE, "strdup");
+			break;
+		case 'n':
+			empty_line = false;
+			break;
+		case 'o':
+			if ((out_file = strdup(optarg)) == NULL)
+				err(EXIT_FAILURE, "strdup");
+			break;
+		case 'p':
+			if ((prompt = strdup(optarg)) == NULL)
+				err(EXIT_FAILURE, "strdup");
+			prompt_len = strlen(prompt);
+			break;
+		case 'h':
+		default:
+			usage();
+			/* NOTREACHED */
+		}
+	}
+	argc -= optind;
+	argv += optind;
 
-	if (term_name == NULL)
-		errx(EXIT_FAILURE, "environment TERM is not set");
+	if (argc > 1)
+		usage();
 
-	switch (tgetent(NULL, term_name)) {
-	case -1: err(EXIT_FAILURE, "tgetent");
-	case 0: errx(EXIT_FAILURE, "no termcap entry found for %s", term_name);
-	}
+	if (argc == 1)
+		if ((dir = strdup(argv[0])) == NULL)
+			err(EXIT_FAILURE, "strdup");
+
+	if (in_file == NULL)
+		if (asprintf(&in_file, "%s/in", dir) == -1)
+			err(EXIT_FAILURE, "asprintf");
+
+	if (out_file == NULL)
+		if (asprintf(&out_file, "%s/out", dir) == -1)
+			err(EXIT_FAILURE, "asprintf");
 
 	if (isatty(fd) == 0)
 		err(EXIT_FAILURE, "isatty");
@@ -47,7 +126,14 @@ main(void)
 	if (tcgetattr(fd, &term) == -1)
 		err(EXIT_FAILURE, "tcgetattr");
 
-	cfmakeraw(&term);
+	/* TODO: clean up this block.  copied from cfmakeraw(3) */
+	term.c_iflag &= ~(IMAXBEL|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON);
+//        term.c_oflag &= ~OPOST;
+	term.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
+	term.c_cflag &= ~(CSIZE|PARENB);
+	term.c_cflag |= CS8;
+	term.c_cc[VMIN] = 1;
+	term.c_cc[VTIME] = 0;
 
 	if (tcsetattr(fd, TCSANOW, &term) == -1)
 		err(EXIT_FAILURE, "tcsetattr");
@@ -55,13 +141,67 @@ main(void)
 	setbuf(stdin, NULL);
 	setbuf(stdout, NULL);
 
-	while ((c = getchar()) != 13) {
-		if (sl_keystroke(sl, c) == -1)
-			errx(EXIT_FAILURE, "sl_keystroke");
-		printf("\r\033[2K%s", sl->buf);
+	/* open external source */
+	snprintf(tail_cmd, sizeof tail_cmd, "exec tail -n %zd -f %s",
+	    history_len, out_file);
+	if ((tail_fh = popen(tail_cmd, "r")) == NULL)
+		err(EXIT_FAILURE, "unable to open pipe to tail command");
+
+	pfd[0].fd = fd;
+	pfd[0].events = POLLIN;
+
+	pfd[1].fd = fileno(tail_fh);
+	pfd[1].events = POLLIN;
+
+	/* print initial prompt */
+	fputs(prompt, stdout);
+
+	for (;;) {
+		poll(pfd, 2, INFTIM);
+
+		/* carriage return and erase the whole line */
+		fputs("\r\033[2K", stdout);
+
+		/* handle keyboard intput */
+		if (pfd[0].revents & POLLIN) {
+			c = getchar();
+			if (c == 13) {	/* return */
+				if (sl->len == 0 && empty_line == false)
+					continue;
+				line_output(sl, in_file);
+				sl_reset(sl);
+			}
+			if (sl_keystroke(sl, c) == -1)
+				errx(EXIT_FAILURE, "sl_keystroke");
+		}
+
+		/* handle tail command error and its broken pipe */
+		if (pfd[1].revents & POLLHUP)
+			break;
+
+		/* handle file intput */
+		if (pfd[1].revents & POLLIN) {
+			char buf[BUFSIZ];
+			ssize_t n = read(pfd[1].fd, buf, sizeof buf);
+			if (n == 0)
+				errx(EXIT_FAILURE, "tail command exited");
+			if (n == -1)
+				err(EXIT_FAILURE, "read");
+			if (write(STDOUT_FILENO, buf, n) == -1)
+				err(EXIT_FAILURE, "write");
+			putchar('\a');	/* ring the bell on external input */
+		}
+
+		/* show current input line */
+		fputs(prompt, stdout);
+		fputs(sl->buf, stdout);
+
+		if (sl->cur < sl->len) {	/* move the cursor */
+			putchar('\r');
+			/* HACK: because \033[0C does the same as \033[1C */
+			if (sl->cur + prompt_len > 0)
+				printf("\033[%zdC", sl->cur + prompt_len);
+		}
 	}
-
-	puts("\r");
-
 	return EXIT_SUCCESS;
 }
diff --git a/slackline.c b/slackline.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdbool.h>
 
 #include "slackline.h"
 
@@ -18,9 +19,7 @@ sl_init(void)
 		return NULL;
 	}
 
-	sl->buf[0] = '\0';
-	sl->len = 0;
-	sl->cur = 0;
+	sl_reset(sl);
 
 	return sl;
 }
@@ -32,14 +31,54 @@ sl_free(struct slackline *sl)
 	free(sl);
 }
 
+void
+sl_reset(struct slackline *sl)
+{
+	sl->buf[0] = '\0';
+	sl->len = 0;
+	sl->cur = 0;
+	sl->esc = ESC_NONE;
+}
+
 int
 sl_keystroke(struct slackline *sl, int key)
 {
 	if (sl == NULL || sl->len < sl->cur)
 		return -1;
 
+	/* handle escape sequences */
+	switch (sl->esc) {
+	case ESC_NONE:
+		break;
+	case ESC:
+		sl->esc = key == '[' ? ESC_BRACKET : ESC_NONE;
+		return 0;
+	case ESC_BRACKET:
+		switch (key) {
+		case 'A':	/* up    */
+		case 'B':	/* down  */
+			break;
+		case 'C':	/* right */
+			if (sl->cur < sl->len)
+				sl->cur++;
+			break;
+		case 'D':	/* left */
+			if (sl->cur > 0)
+				sl->cur--;
+			break;
+		case 'H':	/* Home  */
+			sl->cur = 0;
+			break;
+		case 'F':	/* End   */
+			sl->cur = sl->len;
+			break;
+		}
+		sl->esc = ESC_NONE;
+		return 0;
+	}
+
 	/* add character to buffer */
-	if (key >= 32 && key <= 127) {
+	if (key >= 32 && key < 127) {
 		if (sl->cur < sl->len) {
 			memmove(sl->buf + sl->cur + 1, sl->buf + sl->cur,
 			    sl->len - sl->cur);
@@ -54,12 +93,19 @@ sl_keystroke(struct slackline *sl, int key)
 
 	/* handle ctl keys */
 	switch (key) {
-	case 8:	/* backspace */
+	case 27:	/* Escape */
+		sl->esc = ESC;
+		break;
+	case 127:	/* backspace */
+	case 8:		/* backspace */
 		if (sl->cur == 0)
 			break;
+		if (sl->cur < sl->len)
+			memmove(sl->buf + sl->cur - 1, sl->buf + sl->cur,
+			    sl->len - sl->cur);
 		sl->cur--;
 		sl->len--;
-		sl->buf[sl->cur] = '\0';
+		sl->buf[sl->len] = '\0';
 		break;
 	}
 
diff --git a/slackline.h b/slackline.h
@@ -1,23 +1,21 @@
 #ifndef SLACKLIINE_H
 #define SLACKLIINE_H
 
-/*
- * +-+-+-+-+-+
- * |c|c|c|0|0|
- * +-+-+-+-+-+
- *      ^   ^
- *     len  bufsize
- */
+#include <stdbool.h>
+
+enum esc_seq {ESC_NONE, ESC, ESC_BRACKET};
 
 struct slackline {
 	char *buf;
 	size_t bufsize;
 	size_t len;
 	size_t cur;
+	enum esc_seq esc;
 };
 
-struct slackline * sl_init(void);
-void sl_free(struct slackline *);
+struct slackline *sl_init(void);
+void sl_free(struct slackline *sl);
+void sl_reset(struct slackline *sl);
 int sl_keystroke(struct slackline *sl, int key);
 
 #endif