-/* See LICENSE file for copyright and license details. */
+/* See LICENSE file for copyright and license details.
+ *
+ * Simple terminal daemon is a terminal emulator. It can be used in
+ * combination with simple terminal to emulate a mostly VT100-compatible
+ * terminal.
+ *
+ * In this process std works like a filter. It reads data from a
+ * pseudo-terminal and parses the escape sequences and transforms them
+ * into an ed(1)-like language. The resulting data is buffered and
+ * written to stdout.
+ * Parallely it reads data from stdin and parses and executes the
+ * commands. The resulting data is written to the pseudo-terminal.
+ */
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#if !(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)
+#include <pty.h>
+#endif
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
-/* TODO: add the necessary code into here, which is going to be fork()ed from
- * st if this isn't an attach process */
+#define LENGTH(x) (sizeof(x) / sizeof((x)[0]))
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+
+typedef struct {
+ unsigned char data[BUFSIZ];
+ int s, e;
+ int n;
+} RingBuffer;
+
+static void buffer(char c);
+static void cmd(const char *cmdstr, ...);
+static void getpty(void);
+static void movea(int x, int y);
+static void mover(int x, int y);
+static void parsecmd(void);
+static void parseesc(void);
+static void scroll(int l);
+static void shell(void);
+static void sigchld(int n);
+static char unbuffer(void);
+
+static int cols = 80, lines = 25;
+static int cx = 0, cy = 0;
+static int c;
+static int ptm, pts;
+static _Bool bold, digit, qmark;
+static pid_t pid;
+static RingBuffer buf;
+static FILE *fptm;
+
+void
+buffer(char c) {
+ if(buf.n < LENGTH(buf.data))
+ buf.n++;
+ else
+ buf.s = (buf.s + 1) % LENGTH(buf.data);
+ buf.data[buf.e++] = c;
+ buf.e %= LENGTH(buf.data);
+}
+
+void
+cmd(const char *cmdstr, ...) {
+ va_list ap;
+
+ putchar('\n');
+ putchar(':');
+ va_start(ap, cmdstr);
+ vfprintf(stdout, cmdstr, ap);
+ va_end(ap);
+}
+
+void
+movea(int x, int y) {
+ x = MAX(x, cols);
+ y = MAX(y, lines);
+ cx = x;
+ cy = y;
+ cmd("seek(%d,%d)", x, y);
+}
+
+void
+mover(int x, int y) {
+ movea(cx + x, cy + y);
+}
+
+void
+parsecmd(void) {
+}
+
+void
+parseesc(void) {
+ int i, j;
+ int arg[16];
+
+ memset(arg, 0, LENGTH(arg));
+ c = getc(fptm);
+ switch(c) {
+ case '[':
+ c = getc(fptm);
+ for(j = 0; j < LENGTH(arg);) {
+ if(isdigit(c)) {
+ digit = 1;
+ arg[j] *= 10;
+ arg[j] += c - '0';
+ }
+ else if(c == '?')
+ qmark = 1;
+ else if(c == ';') {
+ if(!digit)
+ errx(EXIT_FAILURE, "syntax error");
+ digit = 0;
+ j++;
+ }
+ else {
+ if(digit) {
+ digit = 0;
+ j++;
+ }
+ break;
+ }
+ c = getc(fptm);
+ }
+ switch(c) {
+ case '@':
+ break;
+ case 'A':
+ mover(0, j ? arg[0] : 1);
+ break;
+ case 'B':
+ mover(0, j ? -arg[0] : -1);
+ break;
+ case 'C':
+ mover(j ? arg[0] : 1, 0);
+ break;
+ case 'D':
+ mover(j ? -arg[0] : -1, 0);
+ break;
+ case 'E':
+ /* movel(j ? arg[0] : 1); */
+ break;
+ case 'F':
+ /* movel(j ? -arg[0] : -1); */
+ break;
+ case '`':
+ case 'G':
+ movea(j ? arg[0] : 1, cy);
+ break;
+ case 'f':
+ case 'H':
+ movea(arg[1] ? arg[1] : 1, arg[0] ? arg[0] : 1);
+ case 'L':
+ /* insline(j ? arg[0] : 1); */
+ break;
+ case 'M':
+ /* delline(j ? arg[0] : 1); */
+ break;
+ case 'P':
+ break;
+ case 'S':
+ scroll(j ? arg[0] : 1);
+ break;
+ case 'T':
+ scroll(j ? -arg[0] : -1);
+ break;
+ case 'd':
+ movea(cx, j ? arg[0] : 1);
+ break;
+ case 'm':
+ for(i = 0; i < j; i++) {
+ if(arg[i] >= 30 && arg[i] <= 37)
+ cmd("#%d", arg[i] - 30);
+ if(arg[i] >= 40 && arg[i] <= 47)
+ cmd("|%d", arg[i] - 40);
+ /* xterm bright colors */
+ if(arg[i] >= 90 && arg[i] <= 97)
+ cmd("#%d", arg[i] - 90);
+ if(arg[i] >= 100 && arg[i] <= 107)
+ cmd("|%d", arg[i] - 100);
+ switch(arg[i]) {
+ case 0:
+ case 22:
+ if(bold)
+ cmd("bold");
+ case 1:
+ if(!bold)
+ cmd("bold");
+ break;
+ }
+ }
+ break;
+ }
+ break;
+ default:
+ putchar('\033');
+ ungetc(c, fptm);
+ }
+}
+
+void
+scroll(int l) {
+ cmd("seek(%d,%d)", cx, cy + l);
+}
+
+void
+getpty(void) {
+ char *ptsdev;
+
+#if defined(_GNU_SOURCE)
+ ptm = getpt();
+#elif _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
+ ptm = posix_openpt(O_RDWR);
+#else
+ ptm = open("/dev/ptmx", O_RDWR);
+ if(ptm == -1)
+ if(openpty(&ptm, &pts, NULL, NULL, NULL) == -1)
+ err(EXIT_FAILURE, "cannot open pty");
+#endif
+#if defined(_XOPEN_SOURCE)
+ if(ptm != -1) {
+ if(grantpt(ptm) == -1)
+ err(EXIT_FAILURE, "cannot grant access to pty");
+ if(unlockpt(ptm) == -1)
+ err(EXIT_FAILURE, "cannot unlock pty");
+ ptsdev = ptsname(ptm);
+ if(!ptsdev)
+ err(EXIT_FAILURE, "slave pty name undefined");
+ pts = open(ptsdev, O_RDWR);
+ if(pts == -1)
+ err(EXIT_FAILURE, "cannot open slave pty");
+ }
+ else
+ err(EXIT_FAILURE, "cannot open pty");
+#endif
+}
+
+void
+shell(void) {
+ static char *shell = NULL;
+
+ if(!shell && !(shell = getenv("SHELL")))
+ shell = "/bin/sh";
+ pid = fork();
+ switch(pid) {
+ case -1:
+ err(EXIT_FAILURE, "cannot fork");
+ case 0:
+ setsid();
+ dup2(pts, STDIN_FILENO);
+ dup2(pts, STDOUT_FILENO);
+ dup2(pts, STDERR_FILENO);
+ close(ptm);
+ putenv("TERM=vt102");
+ execvp(shell, NULL);
+ break;
+ default:
+ close(pts);
+ signal(SIGCHLD, sigchld);
+ }
+}
+
+void
+sigchld(int n) {
+ int ret;
+
+ if(waitpid(pid, &ret, 0) == -1)
+ err(EXIT_FAILURE, "waiting for child failed");
+ if(WIFEXITED(ret))
+ exit(WEXITSTATUS(ret));
+ else
+ exit(EXIT_SUCCESS);
+}
+
+char
+unbuffer(void) {
+ char c;
+
+ c = buf.data[buf.s++];
+ buf.s %= LENGTH(buf.data);
+ buf.n--;
+ return c;
+}
+
+int
+main(int argc, char *argv[]) {
+ fd_set rfds;
+
+ if(argc == 2 && !strcmp("-v", argv[1]))
+ errx(EXIT_SUCCESS, "std-"VERSION", © 2008 Matthias-Christian Ott");
+ else if(argc == 1)
+ errx(EXIT_FAILURE, "usage: std [-v]");
+ getpty();
+ shell();
+ FD_ZERO(&rfds);
+ FD_SET(STDIN_FILENO, &rfds);
+ FD_SET(ptm, &rfds);
+ if(!(fptm = fdopen(ptm, "r+")))
+ err(EXIT_FAILURE, "cannot open pty");
+ if(fcntl(ptm, F_SETFL, O_NONBLOCK) == -1)
+ err(EXIT_FAILURE, "cannot set pty to non-blocking mode");
+ if(fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK) == -1)
+ err(EXIT_FAILURE, "cannot set stdin to non-blocking mode");
+ for(;;) {
+ if(select(MAX(ptm, STDIN_FILENO) + 1, &rfds, NULL, NULL, NULL) == -1)
+ err(EXIT_FAILURE, "cannot select");
+ if(FD_ISSET(ptm, &rfds)) {
+ for(;;) {
+ if((c = getc(fptm)) == EOF) {
+ if(feof(fptm)) {
+ FD_CLR(ptm, &rfds);
+ fflush(fptm);
+ break;
+ }
+ if(errno != EAGAIN)
+ err(EXIT_FAILURE, "cannot read from pty");
+ fflush(stdout);
+ break;
+ }
+ switch(c) {
+ case '\033':
+ parseesc();
+ break;
+ default:
+ putchar(c);
+ }
+ }
+ fflush(stdout);
+ }
+ if(FD_ISSET(STDIN_FILENO, &rfds)) {
+ for(;;) {
+ if((c = getchar()) == EOF) {
+ if(feof(stdin)) {
+ FD_CLR(STDIN_FILENO, &rfds);
+ fflush(fptm);
+ break;
+ }
+ if(errno != EAGAIN)
+ err(EXIT_FAILURE, "cannot read from stdin");
+ fflush(fptm);
+ break;
+ }
+ switch(c) {
+ case ':':
+ parsecmd();
+ break;
+ default:
+ putc(c, fptm);
+ }
+ }
+ fflush(fptm);
+ }
+ }
+ return 0;
+}
Got questions, comments, patches, etc.? Contact Jason Woofenden