client: Add readline support to empire client

Readline provides fancy command line editing such as <Arrow Up> for
previous commands and CTRL+A to jump to the beginning of the line.

This patch does not add any completion on <tab> key, a TODO, if you
will.

A new command line flag, -H, turns on saving the history to disk.
This may have security implications on shared computers, as all
commands are saved as-is.  Thus "change re 1234" would be logged
directly to the file.

Signed-off-by: Martin Haukeli <martin.haukeli@gmail.com>

Rebase on top of preparatory work, fix a few bugs, and tidy up:

* Update the standalone client build, too.

* Fix the Windows build.

* Keep command line options sorted case-insensitively.

* Error out when $HOME is unset and getpwuid() fails, just like we do
  for $LOGNAME.

* Give @input_from_rl, @has_rl_input static linkage.

* @has_rl_input is a flag, not a counter, set and test it accordingly.

* Save all input in history, not just commands.  Martin's attempt to
  recognize commands works only as long as the server sends prompts
  faster than the user sends input.  Drop that part, and update commit
  message accordingly.

* Fix recv_input() not to truncate value of strlen() to int, and to
  use memmove() for updating @input_from_rl in place.

* Clean up whitespace in a few places.

* Tweak commit message.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

Make.mk

@@ -432,5 +432,5 @@ $(srcdir)/src/client/config.h.in: src/client/configure.ac src/client/aclocal.m4
 	cd $(dir $@) && autoheader
 	touch $@
 
-$(srcdir)/src/client/aclocal.m4: m4/ax_lib_socket_nsl.m4 m4/my_terminfo.m4 m4/my_windows_api.m4
+$(srcdir)/src/client/aclocal.m4: m4/ax_lib_readline.m4 m4/ax_lib_socket_nsl.m4 m4/my_terminfo.m4 m4/my_windows_api.m4
 	cat $^ >$@

configure.ac

@@ -73,6 +73,7 @@ LIBS_util="$LIBS"
 LIBS="$LIBS_SOCKETS $LIBS"
 AX_LIB_SOCKET_NSL
 LIBS_server="$LIBS"
+AX_LIB_READLINE
 
 
 ### Checks for header files

m4/ax_lib_readline.m4

@@ -0,0 +1,107 @@
+# ===========================================================================
+#      http://www.gnu.org/software/autoconf-archive/ax_lib_readline.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_LIB_READLINE
+#
+# DESCRIPTION
+#
+#   Searches for a readline compatible library. If found, defines
+#   `HAVE_LIBREADLINE'. If the found library has the `add_history' function,
+#   sets also `HAVE_READLINE_HISTORY'. Also checks for the locations of the
+#   necessary include files and sets `HAVE_READLINE_H' or
+#   `HAVE_READLINE_READLINE_H' and `HAVE_READLINE_HISTORY_H' or
+#   'HAVE_HISTORY_H' if the corresponding include files exists.
+#
+#   The libraries that may be readline compatible are `libedit',
+#   `libeditline' and `libreadline'. Sometimes we need to link a termcap
+#   library for readline to work, this macro tests these cases too by trying
+#   to link with `libtermcap', `libcurses' or `libncurses' before giving up.
+#
+#   Here is an example of how to use the information provided by this macro
+#   to perform the necessary includes or declarations in a C file:
+#
+#     #ifdef HAVE_LIBREADLINE
+#     #  if defined(HAVE_READLINE_READLINE_H)
+#     #    include <readline/readline.h>
+#     #  elif defined(HAVE_READLINE_H)
+#     #    include <readline.h>
+#     #  else /* !defined(HAVE_READLINE_H) */
+#     extern char *readline ();
+#     #  endif /* !defined(HAVE_READLINE_H) */
+#     char *cmdline = NULL;
+#     #else /* !defined(HAVE_READLINE_READLINE_H) */
+#       /* no readline */
+#     #endif /* HAVE_LIBREADLINE */
+#
+#     #ifdef HAVE_READLINE_HISTORY
+#     #  if defined(HAVE_READLINE_HISTORY_H)
+#     #    include <readline/history.h>
+#     #  elif defined(HAVE_HISTORY_H)
+#     #    include <history.h>
+#     #  else /* !defined(HAVE_HISTORY_H) */
+#     extern void add_history ();
+#     extern int write_history ();
+#     extern int read_history ();
+#     #  endif /* defined(HAVE_READLINE_HISTORY_H) */
+#       /* no history */
+#     #endif /* HAVE_READLINE_HISTORY */
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Ville Laurikari <vl@iki.fi>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 6
+
+AU_ALIAS([VL_LIB_READLINE], [AX_LIB_READLINE])
+AC_DEFUN([AX_LIB_READLINE], [
+  AC_CACHE_CHECK([for a readline compatible library],
+                 ax_cv_lib_readline, [
+    ORIG_LIBS="$LIBS"
+    for readline_lib in readline edit editline; do
+      for termcap_lib in "" termcap curses ncurses; do
+        if test -z "$termcap_lib"; then
+          TRY_LIB="-l$readline_lib"
+        else
+          TRY_LIB="-l$readline_lib -l$termcap_lib"
+        fi
+        LIBS="$ORIG_LIBS $TRY_LIB"
+        AC_TRY_LINK_FUNC(readline, ax_cv_lib_readline="$TRY_LIB")
+        if test -n "$ax_cv_lib_readline"; then
+          break
+        fi
+      done
+      if test -n "$ax_cv_lib_readline"; then
+        break
+      fi
+    done
+    if test -z "$ax_cv_lib_readline"; then
+      ax_cv_lib_readline="no"
+    fi
+    LIBS="$ORIG_LIBS"
+  ])
+
+  if test "$ax_cv_lib_readline" != "no"; then
+    LIBS="$LIBS $ax_cv_lib_readline"
+    AC_DEFINE(HAVE_LIBREADLINE, 1,
+              [Define if you have a readline compatible library])
+    AC_CHECK_HEADERS(readline.h readline/readline.h)
+    AC_CACHE_CHECK([whether readline supports history],
+                   ax_cv_lib_readline_history, [
+      ax_cv_lib_readline_history="no"
+      AC_TRY_LINK_FUNC(add_history, ax_cv_lib_readline_history="yes")
+    ])
+    if test "$ax_cv_lib_readline_history" = "yes"; then
+      AC_DEFINE(HAVE_READLINE_HISTORY, 1,
+                [Define if your readline library has \`add_history'])
+      AC_CHECK_HEADERS(history.h readline/history.h)
+    fi
+  fi
+])dnl

man/empire.6

@@ -39,6 +39,11 @@ Use UTF-8 rather than ASCII character set.
 This requires server version 4.2.21 or later, and a terminal that
 understands UTF-8.
 .TP
+.B \-H
+Save readline command history to file.
+.IP
+Only available when compiled with readline and history support.
+.TP
 .B \-v
 Print version information and exit.
 .TP

src/client/configure.ac

@@ -58,6 +58,7 @@ if test "$Windows_API" = yes; then
 	AC_LIBOBJ([w32/w32io])
 	AC_LIBOBJ([w32/w32sockets])
 fi
+AX_LIB_READLINE
 
 
 ### Checks for header files.

src/client/main.c

@@ -40,6 +40,7 @@
 #include <string.h>
 #ifdef _WIN32
 #include <windows.h>
+#include <shlobj.h>
 #include "sys/socket.h"
 #else
 #include <pwd.h>
@@ -55,6 +56,7 @@
 
 struct passwd {
     char *pw_name;
+    char *pw_dir;
 };
 
 static struct passwd *w32_getpw(void);
@@ -72,6 +74,9 @@ print_usage(char *program_name)
 	   "  -r              Restricted mode, no redirections\n"
 	   "  -s [HOST:]PORT  Specify server HOST and PORT\n"
 	   "  -u              Use UTF-8\n"
+#ifdef HAVE_READLINE_HISTORY
+	   "  -H              Save readline command history to file\n"
+#endif /* HAVE_READLINE_HISTORY */
 	   "  -h              display this help and exit\n"
 	   "  -v              display version information and exit\n",
 	   program_name);
@@ -82,6 +87,7 @@ main(int argc, char **argv)
 {
     int opt;
     char *auxfname = NULL;
+    int use_history_file = 0;
     int send_kill = 0;
     char *host = NULL;
     char *port = NULL;
@@ -90,14 +96,20 @@ main(int argc, char **argv)
     char *country;
     char *passwd;
     char *uname;
+    char *udir;
     char *colon;
     int sock;
 
-    while ((opt = getopt(argc, argv, "2:krs:uhv")) != EOF) {
+    while ((opt = getopt(argc, argv, "2:krs:uHhv")) != EOF) {
 	switch (opt) {
 	case '2':
 	    auxfname = optarg;
 	    break;
+#ifdef HAVE_READLINE_HISTORY
+	case 'H':
+	    use_history_file = 1;
+	    break;
+#endif /* HAVE_READLINE_HISTORY */
 	case 'k':
 	    send_kill = 1;
 	    break;
@@ -146,7 +158,8 @@ main(int argc, char **argv)
     if (!host)
 	host = empirehost;
     uname = getenv("LOGNAME");
-    if (uname == NULL) {
+    udir = getenv("HOME");
+    if (!uname || !udir) {
 	struct passwd *pwd;
 
 	pwd = getpwuid(getuid());
@@ -154,7 +167,10 @@ main(int argc, char **argv)
 	    fprintf(stderr, "You don't exist.  Go away\n");
 	    exit(1);
 	}
+	if (!uname)
 	    uname = pwd->pw_name;
+	if (!udir)
+	    udir = pwd->pw_dir;
     }
     if (*ap) {
 	fprintf(stderr, "%s: extra operand %s\n", argv[0], *ap);
@@ -172,6 +188,12 @@ main(int argc, char **argv)
 
     sock = tcp_connect(host, port);
 
+    if (use_history_file) {
+	history_file = malloc(1024);
+	strncpy(history_file, udir, 1000);
+	strcat(history_file, "/.empire.history");
+    }
+
     if (!login(sock, uname, country, passwd, send_kill, utf8))
 	exit(1);
 
@@ -183,12 +205,13 @@ main(int argc, char **argv)
 
 #ifdef _WIN32
 /*
- * Get Windows user name
+ * Get Windows user name and directory
  */
 static struct passwd *
 w32_getpw(void)
 {
     static char unamebuf[128];
+    static char udirbuf[MAX_PATH];
     static struct passwd pwd;
     DWORD unamesize;
 
@@ -199,6 +222,9 @@ w32_getpw(void)
 	    pwd.pw_name = "nobody";
     } else
 	pwd.pw_name = "nobody";
+    if (SUCCEEDED(SHGetFolderPathA(NULL, CSIDL_PROFILE, NULL, 0, udirbuf))
+	&& strlen(udirbuf) == 0)
+	pwd.pw_dir = udirbuf;
     return &pwd;
 }
 

src/client/misc.h

@@ -44,6 +44,7 @@ extern char empireport[];
 extern int eight_bit_clean;
 extern FILE *auxfp;
 extern int restricted;
+extern char *history_file;
 
 #ifdef HAVE_CURSES_TERMINFO
 void getsose(void);

src/client/play.c

@@ -51,6 +51,28 @@
 #include "ringbuf.h"
 #include "secure.h"
 
+#ifdef HAVE_LIBREADLINE
+#  if defined(HAVE_READLINE_READLINE_H)
+#    include <readline/readline.h>
+#  elif defined(HAVE_READLINE_H)
+#    include <readline.h>
+#  else /* !defined(HAVE_READLINE_H) */
+extern char *readline ();
+#  endif /* !defined(HAVE_READLINE_H) */
+#endif /* HAVE_LIBREADLINE */
+
+#ifdef HAVE_READLINE_HISTORY
+#  if defined(HAVE_READLINE_HISTORY_H)
+#    include <readline/history.h>
+#  elif defined(HAVE_HISTORY_H)
+#    include <history.h>
+#  else /* !defined(HAVE_HISTORY_H) */
+extern void add_history ();
+extern int write_history ();
+extern int read_history ();
+#  endif /* !defined(HAVE_HISTORY_H) */
+#endif /* HAVE_READLINE_HISTORY */
+
 #define EOF_COOKIE "ctld\n"
 #define INTR_COOKIE "aborted\n"
 
@@ -414,6 +436,24 @@ recv_output(int sock)
     return n;
 }
 
+char *history_file = NULL;
+#ifdef HAVE_LIBREADLINE
+static char *input_from_rl;
+static int has_rl_input;
+
+static void
+input_handler(char *line)
+{
+    input_from_rl = line;
+    has_rl_input = 1;
+    rl_already_prompted = 1;
+#ifdef HAVE_READLINE_HISTORY
+    if (line && *line)
+	add_history(line);
+#endif /* HAVE_READLINE_HISTORY */
+}
+#endif /* HAVE_LIBREADLINE */
+
 /*
  * Receive player input from @fd into @inbuf.
  * Return 1 on receipt of input, zero on EOF, -1 on error.
@@ -423,7 +463,32 @@ recv_input(int fd, struct ring *inbuf)
 {
     int n;
     int res = 1;
+#ifdef HAVE_LIBREADLINE
+    size_t len;
 
+    if (fd == 0) {
+	if (!has_rl_input)
+	    rl_callback_read_char();
+	if (!has_rl_input)
+	    return 1;
+	if (input_from_rl) {
+	    len = strlen(input_from_rl);
+	    n = ring_space(inbuf);
+	    assert(n);
+	    if (len >= (size_t)n) {
+		ring_putm(inbuf, input_from_rl, n);
+		memmove(input_from_rl, input_from_rl + n, len - n + 1);
+	    } else {
+		ring_putm(inbuf, input_from_rl, len);
+		ring_putc(inbuf, '\n');
+		free(input_from_rl);
+		has_rl_input = 0;
+		n = len + 1;
+	    }
+	} else
+	    n = 0;
+    } else
+#endif
 	n = ring_from_file(inbuf, fd);
     if (n < 0)
 	return -1;
@@ -490,6 +555,7 @@ play(int sock)
     int send_eof;		/* need to send EOF_COOKIE */
     fd_set rdfd, wrfd;
     int n;
+    int ret = -1;
 
     sa.sa_flags = 0;
     sigemptyset(&sa.sa_mask);
@@ -497,6 +563,14 @@ play(int sock)
     sigaction(SIGINT, &sa, NULL);
     sa.sa_handler = SIG_IGN;
     sigaction(SIGPIPE, &sa, NULL);
+#ifdef HAVE_LIBREADLINE
+#ifdef HAVE_READLINE_HISTORY
+    if (history_file)
+	read_history(history_file);
+#endif /* HAVE_READLINE_HISTORY */
+    rl_bind_key('\t', rl_insert);  /* Disable tab completion */
+    rl_callback_handler_install("", input_handler);
+#endif /* HAVE_LIBREADLINE */
 
     ring_init(&inbuf);
     eof_fd0 = partial_line_sent = send_eof = send_intr = 0;
@@ -525,7 +599,7 @@ play(int sock)
 	if (n < 0) {
 	    if (errno != EINTR) {
 		perror("select");
-		return -1;
+		break;
 	    }
 	}
 
@@ -544,7 +618,6 @@ play(int sock)
 		input_fd = 0;
 	    }
 	}
-
 	if (n < 0)
 	    continue;
 
@@ -571,7 +644,7 @@ play(int sock)
 		    sigaction(SIGINT, &sa, NULL);
 		    send_intr = 0;
 		}
-	    } else
+	    } else if (ring_len(&inbuf) > 0)
 		partial_line_sent = ring_peek(&inbuf, -1) != '\n';
 	}
 
@@ -580,7 +653,7 @@ play(int sock)
 	    n = send_input(sock, &inbuf);
 	    if (n < 0) {
 		perror("write socket");
-		return -1;
+		break;
 	    }
 	}
 
@@ -589,10 +662,22 @@ play(int sock)
 	    n = recv_output(sock);
 	    if (n < 0) {
 		perror("read socket");
-		return -1;
+		break;
 	    }
-	    if (n == 0)
+	    if (n == 0) {
-		return 0;
+#ifdef HAVE_LIBREADLINE
+#ifdef HAVE_READLINE_HISTORY
+		if (history_file)
+		    write_history(history_file);
+#endif /* HAVE_READLINE_HISTORY */
+#endif /* HAVE_LIBREADLINE */
+		ret = 0;
+		break;
 	    }
 	}
     }
+#ifdef HAVE_LIBREADLINE
+    rl_callback_handler_remove();
+#endif
+    return ret;
+}

src/client/servcmd.c

@@ -46,6 +46,14 @@
 #include "proto.h"
 #include "secure.h"
 
+#ifdef HAVE_LIBREADLINE
+#  if defined(HAVE_READLINE_READLINE_H)
+#    include <readline/readline.h>
+#  elif defined(HAVE_READLINE_H)
+#    include <readline.h>
+#  endif /* defined(HAVE_READLINE_H) */
+#endif /* HAVE_LIBREADLINE */
+
 int eight_bit_clean;
 FILE *auxfp;
 int restricted;
@@ -131,10 +139,18 @@ static void
 prompt(int code, char *prompt, char *teles)
 {
     char *nl;
+    char pr[1024];
 
     nl = code == C_PROMPT || code == C_INFORM ? "\n" : "";
-    printf("%s%s%s", nl, teles, prompt);
+    snprintf(pr, sizeof(pr), "%s%s", teles, prompt);
+#ifdef HAVE_LIBREADLINE
+    rl_set_prompt(pr);
+    printf("%s", nl);
+    rl_forced_update_display();
+#else  /* !HAVE_LIBREADLINE */
+    printf("%s%s", nl, pr);
     fflush(stdout);
+#endif /* !HAVE_LIBREADLINE */
     if (auxfp) {
 	fprintf(auxfp, "%s%s%s", nl, teles, prompt);
 	fflush(auxfp);