util: ucom - micro serial console

Applications/util/Makefile.generic

@@ -72,6 +72,7 @@ SRCS  = \
 	mail.c \
 	man.c \
 	manscan.c \
+	ucom.c \
 	mkfs.c \
 	mode.c \
 	more.c \

Applications/util/fuzix-util.pkg

@@ -119,6 +119,7 @@ f 0755 /bin/uniq        uniq
 f 0755 /bin/uptime      uptime
 f 0755 /bin/uud         uud
 f 0755 /bin/uue         uue
+f 0755 /bin/ucom        ucom
 f 0755 /bin/vile        vile
 l /bin/vile /bin/vi
 f 0755 /bin/wc          wc
@@ -130,3 +131,4 @@ f 0755 /bin/write       write
 f 0755 /bin/xargs       xargs
 f 0755 /bin/yes         yes
 
+f 0655 /usr/man/man1/ucom.1      ucom.1

Applications/util/ucom.1

@@ -0,0 +1,49 @@
+.TH ucom 1 "FUZIX System Utilities" "FUZIX"
+.SH NAME
+ucom \- simple serial console.
+.SH SYNOPSIS
+.B ucom
+[\-s speed] device
+.SH DESCRIPTION
+Simple and minimal terminal emulator program, to use with modems and alike.
+.P
+Just like other terminal emulator progrms
+.B ucom
+supports escape sequence to execute a command in
+.B ucom
+itself.
+.SH OPTIONS
+.TP
+.B "-s speed"
+Set speed of the
+.B device
+in baud before connecting.
+
+.SH COMMANDS
+Commands are executed by first inputing
+.I escape character
+(
+.B ESC
+) which by default is
+.B ^A.
+
+.TP
+.B "ESC q"
+Quit program and restore
+.B device termios
+to the previous settings.
+
+.TP
+.B "ESC ESC"
+Print escape character verbatim.
+
+.SH EXAMPLES
+.P
+ucom /dev/tty2
+.P
+man -s 300 /dev/tty2
+.SH BUGS
+To be found.
+.SH AUTHORS
+Yaroslav Veremenko
+.SH SEE ALSO

Applications/util/ucom.c

@@ -0,0 +1,223 @@
+/* ucom.c - Simple serial console.
+ *
+ * Copyright (C) 2024 Yaroslav Veremenko, All rights reserved.
+ *
+ * This file is part of FUZIX Operating System.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdio.h>
+#include <signal.h>
+#include <termios.h>
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <string.h>
+#include <termio.h>
+#include <errno.h>
+#include <getopt.h>
+#include <sys/wait.h>
+
+static struct termios termsave[2];
+static struct termios termcur[2];
+static int remotefd = -1;
+static speed_t speed = 0;
+static char escape = 1;
+static int opt, i;
+static char buf[2];
+static pid_t child;
+static char *remotename;
+
+static int baud[] = {
+    50,     /* B50 */
+    75,     /* B75 */
+    110,    /* B110 */
+    134,    /* B134 */
+    150,    /* B150 */
+    300,    /* B300 */
+    600,    /* B600 */
+    1200,   /* B1200 */
+    2400,   /* B2400 */
+    4800,   /* B4800 */
+    9600,   /* B9600 */
+    19200,  /* B19200 */
+    38400,  /* B38400 */
+    57600,  /* B57600 */
+    115200, /* B115200 */
+};
+
+static speed_t baudflg[] = {
+    B50,
+    B75,
+    B110,
+    B134,
+    B150,
+    B300,
+    B600,
+    B1200,
+    B2400,
+    B4800,
+    B9600,
+    B19200,
+    B38400,
+    B57600,
+    B115200,
+};
+
+#ifndef uint_fast8_t
+#define uint_fast8_t char
+#endif
+
+#define TTY 0
+#define REMOTE 1
+
+static void term_raw(int fd, int type)
+{
+    tcgetattr(fd, &termsave[type]);
+    memcpy(&termcur[type], &termsave[type], sizeof(struct termios));
+    cfmakeraw(&termcur[type]);
+    termcur[type].c_cc[VMIN] = 1;
+    termcur[type].c_cc[VTIME] = 0;
+    tcsetattr(fd, TCSAFLUSH, &termcur[type]);
+}
+
+static void restore()
+{
+    tcsetattr(0, TCSAFLUSH, &termsave[TTY]);
+    if (remotefd >= 0)
+    {
+        tcsetattr(remotefd, TCSAFLUSH, &termsave[REMOTE]);
+        close(remotefd);
+    }
+}
+
+static void quit()
+{
+    int status;
+    kill(child, SIGHUP);
+    wait(&status);
+}
+
+static void usage()
+{
+    fputs("Micro terminal program.\n"
+        "Usage: ucom [-s SPEED] DEVICE\n\n"
+        "  DEVICE\t- tty or other character device\n"
+        "  -s SPEED\t- set device speed in baud\n"
+        "  ^A\t\t- default escape character\n"
+        "  ESC q\t\t- exit terminal\n", stderr);
+}
+
+int main(int argc, char *argv[])
+{
+    if (isatty(0) != 1)
+    {
+        fputs("fd 0 is not tty\n", stderr);
+        exit(1);
+    }
+
+    while ((opt = getopt(argc, argv, "s:")) != -1)
+    {
+        switch (opt)
+        {
+        case 's':
+            speed = atoi(optarg);
+            for (i = 0; i < sizeof(baud); i++)
+            {
+                if (baud[i] == speed)
+                {
+                    speed = baudflg[i];
+                    break;
+                }
+            }
+            break;
+        default:
+            usage();
+            exit(1);
+            break;
+        }
+    }
+
+    argv += optind;
+	argc -= optind;
+
+    if (argc != 1)
+    {
+        usage();
+        exit(1);
+    }
+
+    remotename = *argv;
+    remotefd = open(remotename, O_RDWR | O_NOCTTY);
+
+    if (remotefd < 0)
+    {
+        perror(remotename);
+        exit(1);
+    }
+
+    term_raw(0, TTY);
+    term_raw(remotefd, REMOTE);
+
+    if (speed > 0)
+    {
+        if (cfsetospeed(&termcur[REMOTE], (speed_t)speed) < 0 ||
+            tcsetattr(remotefd, TCSAFLUSH, &termcur[REMOTE]) < 0)
+        {
+            restore();
+            perror("speed");
+            exit(1);
+        }
+    }
+
+    child = fork();
+    if (child < 0)
+    {
+        restore();
+        perror("fork");
+        exit(1);
+    }
+    if (child == 0)
+    {
+        while (read(remotefd, &buf[0], 1) > 0)
+        {
+            write(0, &buf[0], 1);
+        }
+        fputs("Disconnected\r\n", stderr);
+    }
+    else
+    {
+        uint_fast8_t isEscape = 0;
+        atexit(restore);
+        fprintf(stderr, "Connected. Escape character ^%c\r\n", '@' + escape);
+        while (read(0, &buf[1], 1) > 0)
+        {
+            if (!isEscape && buf[1] == escape)
+            {
+                isEscape = 1;
+                continue;
+            }
+            if (isEscape && buf[1] == 'q')
+            {
+                break;
+            }
+            isEscape = 0;
+            write(remotefd, &buf[1], 1);
+        }
+        quit();
+    }
+}