script: new applet by Pascal Bellard <pascal.bellard AT ads-lu.com>

1 files changed, 195 insertions, 0 deletions

diff --git a/util-linux/script.c b/util-linux/script.c
new file mode 100644
index 0000000..fda726e
--- /dev/null
+++ b/util-linux/script.c
@@ -0,0 +1,195 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * script implementation for busybox
+ *
+ * pascal.bellard@ads-lu.com
+ *
+ * Based on code from util-linux v 2.12r
+ * Copyright (c) 1980
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Licensed under GPLv2 or later, see file License in this tarball for details.
+ */
+
+#include "libbb.h"
+
+struct globals {
+	int child_pid;
+	int attr_ok; /* NB: 0: ok */
+	struct termios tt;
+	const char *fname;
+};
+#define G (*ptr_to_globals)
+#define child_pid (G.child_pid)
+#define attr_ok   (G.attr_ok  )
+#define tt        (G.tt       )
+#define fname     (G.fname    )
+#define INIT_G() do { \
+	PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
+	fname = "typescript"; \
+} while (0)
+
+static void done(void)
+{
+	if (child_pid) { /* we are parent */
+		if (attr_ok == 0)
+			tcsetattr(0, TCSAFLUSH, &tt);
+		if (!(option_mask32 & 8)) /* not -q */
+			printf("Script done, file is %s\n", fname);
+	}
+	exit(0);
+}
+
+#ifdef UNUSED
+static void handle_sigchld(int sig)
+{
+	/* wait for the exited child and exit */
+	while (wait_any_nohang(&sig) > 0)
+		continue;
+	done();
+}
+#endif
+
+#if ENABLE_GETOPT_LONG
+static const char getopt_longopts[] ALIGN1 =
+	"append\0"  No_argument       "a"
+	"command\0" Required_argument "c"
+	"flush\0"   No_argument       "f"
+	"quiet\0"   No_argument       "q"
+	;
+#endif
+
+int script_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
+int script_main(int argc, char *argv[])
+{
+	int opt, pty;
+	int winsz_ok;
+	int mode;
+	struct termios rtt;
+	struct winsize win;
+	char line[32];
+	const char *shell;
+	char shell_opt[] = "-i";
+	char *shell_arg = NULL;
+
+	INIT_G();
+#if ENABLE_GETOPT_LONG
+	applet_long_options = getopt_longopts;
+#endif
+	opt_complementary = "?1"; /* max one arg */
+	opt = getopt32(argv, "ac:fq", &shell_arg);
+	//argc -= optind;
+	argv += optind;
+	if (argv[0]) {
+		fname = argv[0];
+	}
+	mode = O_CREAT|O_TRUNC|O_WRONLY;
+	if (opt & 1) {
+		mode = O_CREAT|O_APPEND|O_WRONLY;
+	}
+	if (opt & 2) {
+		shell_opt[1] = 'c';
+	}
+	if (!(opt & 8)) { /* not -q */
+		printf("Script started, file is %s\n", fname);
+	}
+	shell = getenv("SHELL");
+	if (shell == NULL) {
+		shell = _PATH_BSHELL;
+	}
+
+	pty = getpty(line, sizeof(line));
+	if (pty < 0) {
+		bb_perror_msg_and_die("can't get pty");
+	}
+
+	/* get current stdin's tty params */
+	attr_ok = tcgetattr(0, &tt);
+	winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);
+
+	rtt = tt;
+	cfmakeraw(&rtt);
+	rtt.c_lflag &= ~ECHO;
+	tcsetattr(0, TCSAFLUSH, &rtt);
+
+	/* We exit as soon as child exits */
+	//signal(SIGCHLD, handle_sigchld);
+	signal(SIGCHLD, (void (*)(int)) done);
+
+	child_pid = vfork();
+	if (child_pid < 0) {
+		bb_perror_msg_and_die("vfork");
+	}
+
+	if (child_pid) {
+		/* parent */
+		char buf[256];
+		struct pollfd pfd[2];
+		int outfd;
+		int fd_count = 2;
+		struct pollfd *ppfd = pfd;
+
+		outfd = xopen(fname, mode);
+		pfd[0].fd = 0;
+		pfd[0].events = POLLIN;
+		pfd[1].fd = pty;
+		pfd[1].events = POLLIN;
+		ndelay_on(pty); /* this descriptor is not shared, can do this */
+		/* ndelay_on(0); - NO, stdin can be shared! */
+
+		/* copy stdin to pty master input,
+		 * copy pty master output to stdout and file */
+		/* TODO: don't use full_write's, use proper write buffering */
+		while (fd_count && safe_poll(ppfd, fd_count, -1) > 0) {
+			if (pfd[0].revents) {
+				int count = safe_read(0, buf, sizeof(buf));
+				if (count <= 0) {
+					/* err/eof: don't read anymore */
+					pfd[0].revents = 0;
+					ppfd++;
+					fd_count--;
+				} else {
+					full_write(pty, buf, count);
+				}
+			}
+			if (pfd[1].revents) {
+				int count;
+				errno = 0;
+				count = safe_read(pty, buf, sizeof(buf));
+				if (count <= 0 && errno != EAGAIN) {
+					/* err/eof: don't read anymore */
+					pfd[1].revents = 0;
+					fd_count--;
+				}
+				if (count > 0) {
+					full_write(1, buf, count);
+					full_write(outfd, buf, count);
+					if (opt & 4) { /* -f */
+						fsync(outfd);
+					}
+				}
+			}
+		}
+		done(); /* does not return */
+	}
+
+	/* child: make pty slave to be input, output, error; run shell */
+	close(pty); /* close pty master */
+	/* open pty slave to fd 0,1,2 */
+	close(0);               
+	xopen(line, O_RDWR); /* uses fd 0 */
+	xdup2(0, 1);
+	xdup2(0, 2);
+	/* copy our original stdin tty's parameters to pty */
+	if (attr_ok == 0)
+		tcsetattr(0, TCSAFLUSH, &tt);
+	if (winsz_ok == 0)
+		ioctl(0, TIOCSWINSZ, (char *)&win);
+	/* set pty as a controlling tty */
+	setsid();
+	ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
+
+	/* signal(SIGCHLD, SIG_DFL); - exec does this for us */
+	execl(shell, shell, shell_opt, shell_arg, NULL);
+	bb_simple_perror_msg_and_die(shell);
+}