rawtty

commit 323c6ecd3e909d81832443f44729507ad1f5d9a2
Author: Tomas Hlavaty <tom@logand.com>
Date:   Fri, 15 Feb 2013 20:22:49 +0100

initial commit

Diffstat:
A
.gitignore
 | 
3
+++
A
Makefile
 | 
10
++++++++++
A
rawtty.c
 | 
147
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
rawttytestchild.c
 | 
40
++++++++++++++++++++++++++++++++++++++++

4 files changed, 200 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+rawtty
+rawttytestchild
+*~
diff --git a/Makefile b/Makefile
@@ -0,0 +1,10 @@
+all: rawtty rawttytestchild
+
+rawtty: rawtty.c
+	$(CC) -o $@ $@.c
+
+rawttytestchild: rawttytestchild.c
+	$(CC) -o $@ $@.c
+
+clean:
+	rm -f rawtty rawttytestchild
diff --git a/rawtty.c b/rawtty.c
@@ -0,0 +1,147 @@
+/*
+
+  rawtty -- run program under raw tty
+
+  Copyright (C) 2013 Tomas Hlavaty <tom at logand.com>
+
+  Permission is hereby granted, free of charge, to any person
+  obtaining a copy of this software and associated documentation files
+  (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge,
+  publish, distribute, sublicense, and/or sell copies of the Software,
+  and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+
+*/
+
+#include <termios.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+//#include <stdio.h>
+
+#define BLEN 1024
+
+static int childpipe[2];
+
+static struct termios old;
+static int selfpipe[2];
+
+static int die(char *msg) {
+  write(STDERR_FILENO, "error: ", 7);
+  write(STDERR_FILENO, msg, strlen(msg));
+  write(STDERR_FILENO, "\n", 1);
+  exit(1);
+  return 1;
+}
+
+static void cleanup(void) {
+  tcsetattr(STDIN_FILENO, TCSAFLUSH, &old);
+}
+
+static void setup(void) {
+  isatty(STDIN_FILENO) || die("not on a tty");
+  tcgetattr(STDIN_FILENO, &old) < 0 && die("can't query tty");
+  atexit(cleanup) && die("can't clean up");
+  struct termios raw = old;
+  raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+  raw.c_oflag &= ~(OPOST);
+  raw.c_cflag |= (CS8);
+  raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+  raw.c_cc[VMIN] = 0;
+  raw.c_cc[VTIME] = 0;
+  tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) < 0 && die("can't set raw mode");
+}
+
+static void handler(int signo) {
+  unsigned char n = signo;
+  write(selfpipe[1], &n, 1);
+  //fprintf(stderr, "handler %d\n", signo);
+}
+
+static void nonblocking(int fd) {
+  int x = fcntl(fd, F_GETFL);
+  x < 0 && die("F_GETFL");
+  fcntl(fd, F_SETFL, x | O_NONBLOCK) < 0 && die("O_NONBLOCK");
+}
+
+static void parent() {
+  close(childpipe[0]) == -1 && die("parent can't close read end");
+  dup2(childpipe[1], STDOUT_FILENO);
+  close(childpipe[1]) == -1 && die("parent can't close write end");
+  nonblocking(STDOUT_FILENO);
+  pipe(selfpipe) == -1 && die("can't create self pipe");
+  nonblocking(selfpipe[0]);
+  nonblocking(selfpipe[1]);
+  signal(SIGCHLD, handler);
+  fd_set rfds;
+  fd_set wfds;
+  char buf[BLEN];
+  int abuf = 0, zbuf = 0;
+  for(;;) {
+    FD_ZERO(&rfds);
+    FD_ZERO(&wfds);
+    if(0 < zbuf) FD_SET(STDOUT_FILENO, &wfds);
+    else FD_SET(STDIN_FILENO, &rfds);
+    FD_SET(selfpipe[0], &rfds);
+    switch(select(FD_SETSIZE, &rfds, &wfds, NULL, NULL)) {
+    case -1: EINTR == errno || die("can't select"); break;
+    case 0: die("no data");
+    default:
+      if(FD_ISSET(STDIN_FILENO, &rfds)) {
+        zbuf = read(STDIN_FILENO, buf, BLEN);
+        zbuf < 1 && die("can't read");
+        //if(4 == *buf) die("^d");
+        //if(3 == *buf) die("^c");
+      }
+      else if(FD_ISSET(STDOUT_FILENO, &wfds)) {
+        int n = write(STDOUT_FILENO, buf, zbuf - abuf);
+        n < 1 && die("can't write");
+        abuf += n;
+        if(zbuf <= abuf) abuf = zbuf = 0;
+      }
+      else if(FD_ISSET(selfpipe[0], &rfds)) {
+        unsigned char n;
+        while(0 < read(selfpipe[0], &n, 1));
+        //fprintf(stderr, "sig %d \n", (int) n);
+        exit(0);
+      }
+      else die("unhandled select case");
+    }
+  }
+  //int stat;
+  //wait(&stat);
+}
+
+static void child(char *argv[]) {
+  close(childpipe[1]) == -1 && die("child can't close write end");
+  dup2(childpipe[0], STDIN_FILENO);
+  close(childpipe[0]) == -1 && die("child can't close read end");
+  execvp(argv[1], &argv[1]);
+  die("can't execute");
+}
+
+int main(int argc, char *argv[]) {
+  0 < argc || die("usage: rawtty program [arg...]");
+  setup();
+  pipe(childpipe) == -1 && die("can't create child pipe");
+  switch(fork()) {
+  case -1: die("can't fork");
+  case 0: child(argv);
+  default: parent();
+  }
+  return 0;
+}
diff --git a/rawttytestchild.c b/rawttytestchild.c
@@ -0,0 +1,40 @@
+/*
+
+  rawttytestchild -- test program to be run with rawtty
+
+  Copyright (C) 2013 Tomas Hlavaty <tom at logand.com>
+
+  Permission is hereby granted, free of charge, to any person
+  obtaining a copy of this software and associated documentation files
+  (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge,
+  publish, distribute, sublicense, and/or sell copies of the Software,
+  and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+
+*/
+
+#include <unistd.h>
+#include <stdlib.h>
+
+int main() {
+  unsigned char c;
+  while(0 < read(STDIN_FILENO, &c, 1)) {
+    if(c < 'a' || 'z' < c) break;
+    c += 'A' - 'a';
+    write(STDOUT_FILENO, &c, 1);
+  }
+  return 0;
+}