Mini Shell

#!/usr/bin/sh
# -*- tcl -*-
# The next line is executed by /bin/sh, but not tcl \
exec tclsh "$0" ${1+"$@"}

package require Expect

# Name: autoexpect - generate an Expect script from watching a session
#
# Description:
#
# Given a program name, autoexpect will run that program.  Otherwise
# autoexpect will start a shell.  Interact as desired.  When done, exit
# the program or shell.  Autoexpect will create a script that reproduces
# your interactions.  By default, the script is named script.exp.
# See the man page for more info.
#
# Author: Don Libes, NIST
# Date: June 30 1995
# Version: 1.4b

set filename "script.exp"
set verbose 1
set conservative 0
set promptmode 0
set option_keys ""

proc check_for_following {type} {
	if {![llength [uplevel set argv]]} {
		puts "autoexpect: [uplevel set flag] requires following $type"
		exit 1
	}
}

while {[llength $argv]>0} {
	set flag [lindex $argv 0]
	if {0==[regexp "^-" $flag]} break
	set argv [lrange $argv 1 end]
	switch -- $flag \
	  "-c" {
		set conservative 1
	} "-C" {
		check_for_following character
		lappend option_keys [lindex $argv 0] ctoggle
		set argv [lrange $argv 1 end]
	} "-p" {
		set promptmode 1
	} "-P" {
		check_for_following character
		lappend option_keys [lindex $argv 0] ptoggle
		set argv [lrange $argv 1 end]
	} "-Q" {
		check_for_following character
		lappend option_keys [lindex $argv 0] quote
		set argv [lrange $argv 1 end]
	} "-f" {
		check_for_following filename
		set filename [lindex $argv 0]
		set argv [lrange $argv 1 end]
	} "-quiet" {
		set verbose 0
	} default {
		break
	}
}

#############################################################
# Variables	Descriptions
#############################################################
# userbuf	buffered characters from user
# procbuf	buffered characters from process
# lastkey	last key pressed by user
#		if undefined, last key came from process
# echoing	if the process is echoing
#############################################################

# Handle a character that came from user input (i.e., the keyboard)
proc input {c} {
	global userbuf lastkey

	send -- $c
	append userbuf $lastkey
	set lastkey $c
}

# Handle a null character from the keyboard
proc input_null {} {
	global lastkey userbuf procbuf echoing

	send -null

	if {$lastkey == ""} {
		if {$echoing} {
			sendcmd "$userbuf"
		}
		if {$procbuf != ""} {
			expcmd "$procbuf"
		}
	} else {
		sendcmd "$userbuf"
		if {$echoing} {
			expcmd "$procbuf"
			sendcmd "$lastkey"
		}
	}
	cmd "send -null"
	set userbuf ""
	set procbuf ""
	set lastkey ""
	set echoing 0
}

# Handle a character that came from the process
proc output {s} {
	global lastkey procbuf userbuf echoing

	send_user -raw -- $s

	if {$lastkey == ""} {
		if {!$echoing} {
			append procbuf $s
		} else {
			sendcmd "$userbuf"
			expcmd "$procbuf"
			set echoing 0
			set userbuf ""
			set procbuf $s
		}
		return
	}

	regexp (.)(.*) $s dummy c tail
	if {$c == $lastkey} {
		if {$echoing} {
			append userbuf $lastkey
			set lastkey ""
		} else {
			if {$procbuf != ""} {
				expcmd "$procbuf"
				set procbuf ""
			}
			set echoing 1
		}
		append procbuf $s

		if {[string length $tail]} {
			sendcmd "$userbuf$lastkey"
			set userbuf ""
			set lastkey ""
			set echoing 0
		}
	} else {
		if {!$echoing} {
			expcmd "$procbuf"
		}
		sendcmd "$userbuf$lastkey"
		set procbuf $s
		set userbuf ""
		set lastkey ""
		set echoing 0
	}
}

# rewrite raw strings so that can appear as source code but still reproduce
# themselves.
proc expand {s} {
	regsub -all "\\\\" $s "\\\\\\\\" s
	regsub -all "\r" $s "\\r"  s
	regsub -all "\"" $s "\\\"" s
	regsub -all "\\\[" $s "\\\[" s
	regsub -all "\\\]" $s "\\\]" s
	regsub -all "\\\$" $s "\\\$" s

	return $s
}

# generate an expect command
proc expcmd {s} {
	global promptmode

	if {$promptmode} {
		regexp ".*\[\r\n]+(.*)" $s dummy s
	}

	cmd "expect -exact \"[expand $s]\""
}

# generate a send command
proc sendcmd {s} {
	global send_style conservative

	if {$conservative} {
		cmd "sleep .1"
	}

	cmd "send$send_style -- \"[expand $s]\""
}

# generate any command
proc cmd {s} {
	global fd
	puts $fd "$s"
}

proc verbose_send_user {s} {
	global verbose

	if {$verbose} {
		send_user -- $s
	}
}

proc ctoggle {} {
	global conservative send_style

	if {$conservative} {
		cmd "# conservative mode off - adding no delays"
		verbose_send_user "conservative mode off\n"
		set conservative 0
		set send_style ""
	} else {
		cmd "# prompt mode on - adding delays"
		verbose_send_user "conservative mode on\n"
		set conservative 1
		set send_style " -s"
	}
}

proc ptoggle {} {
	global promptmode

	if {$promptmode} {
		cmd "# prompt mode off - now looking for complete output"
		verbose_send_user "prompt mode off\n"
		set promptmode 0
	} else {
		cmd "# prompt mode on - now looking only for prompts"
		verbose_send_user "prompt mode on\n"
		set promptmode 1
	}
}

# quote the next character from the user
proc quote {} {
	expect_user -re .
	send -- $expect_out(buffer)
}
	

if {[catch {set fd [open $filename w]} msg]} {
	puts $msg
	exit
}
exec chmod +x $filename
verbose_send_user "autoexpect started, file is $filename\n"

# calculate a reasonable #! line
set expectpath /usr/local/bin		;# prepare default
foreach dir [split $env(PATH) :] {	;# now look for real location
	if {[file executable $dir/expect] && ![file isdirectory $dir/expect]} {
		set expectpath $dir
		break
	}
}

cmd "#![set expectpath]/expect -f
#
# This Expect script was generated by autoexpect on [timestamp -format %c]
# Expect and autoexpect were both written by Don Libes, NIST."
cmd {#
# Note that autoexpect does not guarantee a working script.  It
# necessarily has to guess about certain things.  Two reasons a script
# might fail are:
#
# 1) timing - A surprising number of programs (rn, ksh, zsh, telnet,
# etc.) and devices discard or ignore keystrokes that arrive "too
# quickly" after prompts.  If you find your new script hanging up at
# one spot, try adding a short sleep just before the previous send.
# Setting "force_conservative" to 1 (see below) makes Expect do this
# automatically - pausing briefly before sending each character.  This
# pacifies every program I know of.  The -c flag makes the script do
# this in the first place.  The -C flag allows you to define a
# character to toggle this mode off and on.

set force_conservative 0  ;# set to 1 to force conservative mode even if
			  ;# script wasn't run conservatively originally
if {$force_conservative} {
	set send_slow {1 .1}
	proc send {ignore arg} {
		sleep .1
		exp_send -s -- $arg
	}
}

#
# 2) differing output - Some programs produce different output each time
# they run.  The "date" command is an obvious example.  Another is
# ftp, if it produces throughput statistics at the end of a file
# transfer.  If this causes a problem, delete these patterns or replace
# them with wildcards.  An alternative is to use the -p flag (for
# "prompt") which makes Expect only look for the last line of output
# (i.e., the prompt).  The -P flag allows you to define a character to
# toggle this mode off and on.
#
# Read the man page for more info.
#
# -Don

}

cmd "set timeout -1"
if {$conservative} {
	set send_style " -s"
	cmd "set send_slow {1 .1}"
} else {
	set send_style ""
}

if {[llength $argv]>0} {
	eval spawn -noecho $argv
	cmd "spawn $argv"
} else {
	spawn -noecho $env(SHELL)
	cmd "spawn \$env(SHELL)"
}

cmd "match_max 100000"

set lastkey ""
set procbuf ""
set userbuf ""
set echoing 0

remove_nulls 0

eval interact $option_keys {
    -re . {
	input $interact_out(0,string)
    } -o -re .+ {
	output $interact_out(0,string)
    } eof {
	cmd "expect eof"
	return
    }
}

close $fd
verbose_send_user "autoexpect done, file is $filename\n"