#!/bin/ksh
# @(#) te.ksh,where.ksh 2.1.1 97/07/20
# 92/08/31 John H. DuBois III (john@armory.com)
# 92/09/10 added -p option to whence
# 92/10/16 Allow multiple ,-separated targets; added help
# 92/10/21 Added {}
# 93/08/02 Changed name to te to avoid conflict with to
# 94/03/08 Added -c option
# 94/06/29 Added -xpt.  Fixed bug in {} processing which caused all target
#          executables to be substituted for {} as a single word.
# 95/04/23 Added TECMD env var, n option, & rcfile processing
# 95/05/17 Change window title if appropriate
# 96/08/24 Let capital letters turn off options.  Merged te and where.
#          Added aL options.
# 96/09/03 Do not search for absolute paths in $PATH.
# 97/07/20 2.1.1 In 'where' mode, print each match as it is found rather than
#          storing in an array, to avoid 1024-element limit.

# todo: option to cd to directory that 1st file is found in before running
# command.

name=${0##*/}
iUsage="$name [-aAeEfFhlLnsStTvVwW] [-p<path>]"
Usage=\
"Usage: 
$iUsage target[,target,...] [cmd [arg ...]]
$iUsage -c \"cmd [arg ...]\" target [target ...]"

# Only take TECMD from the environment
Debug=false Test=false VERBOSE= notVERBOSE=false Readrc=true CmdGiven=false
ALL= notALL=false NOTITLE= notNOTITLE=false ANYFILE= notANYFILE=false
SYMLINKS= notSYMLINKS=false EXACT= notEXACT=false SHELLPAT= notSHELLPAT=false
listTargets=false where=false types=
rcFile=.terc
searchPath=$PATH

if [ "$name" = where ]; then
    listTargets=true SHELLPAT=1 Readrc=false where=true
fi

while getopts :aAc:eEfFhlLnp:sStTvVwWx opt; do
    case $opt in
    h)
    echo \
"$name: execute commands on commands.
$Usage
Each target is searched for as a command in \$PATH and expanded into its
full filename.  command [arg ...] is then executed with the list of
filenames as additional arguments.  Targets given with absolute paths are
operated on directly without searching for them in \$PATH (as is the behaviour
when a program name is given to the shell to be executed).
If one of the arguments is \"{}\", it is replaced with the list of
filenames and the filenames are not passed as additional arguments.
Targets can be specified either as a comma-separated list followed by the
command and its optional initial arguments, or if the command is given with -c,
as a list of separate arguments following the command (which in this case must
be quoted to make it a single argument if it includes initial arguments to the
command).  
If the environment variable TECMD is set, it provides a default command and
optional initial arguments to it to run if no command is specified (if only
one argument is given and -c is not given).  TECMD may also be assigned a value
in the configuration file described below.
If the environment variables WINTITLE, DISPLAY, and EDITOR are set, and the
command to be run is the same as the value of EDITOR, an xterm escape sequence
is sent to change the window title to the name of the files being edited,
followed by the value of WINTITLE in parentheses.  After editing is completed,
another sequence is sent to change the window title back to the value of
WINTITLE by itself.

Options:
Some of the following options can be set in a configuration file named
\"$rcFile\", which may be in the invoking user's home directory or in the
directory specified by the environment variable UHOME (if both exist,
assignments in the former take precedence).  In this file, values are assigned
to variables in shell style, e.g. \"VARNAME=value\".  To set an option that
does not take a value, use \"VARNAME=1\".  Options given in the configuration
files are overridden by those given on the command line.  Use the upper case
version of a Boolean (on or off) option letter to unset it.  Variable names are
given in parentheses following option descriptions.
Example contents of a $rcFile file:
TECMD=\"vi -c'set ts=4'\"
If this program is invoked as \"where\", the T, s, and n options are turned on.
-a: Execute the command on every instance of the target that occurs in the
    search path, instead of just the first occurance.  (ALL)
-s: Treat filenames as unanchored ksh shell patterns.  This causes e.g. the
    pattern \"bar@(ba|fi)z\" to select filenames that contain the string barbaz
    or barfiz.  See the regexp(M) man page for a description of ksh filename
    patterns.  Patterns are surrounded by implicit '*' characters, causing them
    to be unanchored.  This can be overridden by using '^' and '$' to force a
    match to start at the beginning and end at the end of a filename
    respectively.  Characters that are special to the shell must generally
    be protected from the shell by surrounding them with quotes.  (SHELLPAT)
-e: Used with -s, finds exact (complete) matches only; equivalent to putting ^
    and $ at the start and end of each pattern.  (EXACT)
-f: Find any matching regular file in the search path, regardless of whether it
    is executable or not.  (ANYFILE)
-l: Also find any matching symlink in the search path, regardless of whether
    the file it points to exists or is executable.  (SYMLINKS)
-p<path>: Use <path> as the search path instead of using the value of the PATH
    variable.
-h: Print this help.
-n: Do not read the $rcFile file.
-w: Do not send an xterm title escape sequence.  (NOTITLE)
-v: Print the command before it is run.  (VERBOSE)
-t: Print the command that would be executed, but do not run it.
-T: Print a list of all matching target files, without doing anything to them.
    This turns on the a option."
	exit 0
	;;
    c)
	Cmd=$OPTARG
	CmdGiven=true
	;;
    x)	Debug=true;;
    w)	NOTITLE=1;;
    W)	notNOTITLE=true;;
    n)	Readrc=false;;
    t)	Test=true;;
    T)	listTargets=true;;
    v)	VERBOSE=1;;
    V)	notVERBOSE=true;;
    p)	searchPath=$OPTARG;;
    f)	ANYFILE=1;;
    F)	notANYFILE=true;;
    e)	EXACT=1;;
    E)	notEXACT=true;;
    s)	SHELLPAT=1;;
    S)	notSHELLPAT=true;;
    l)	SYMLINKS=1;;
    L)	notSYMLINKS=true;;
    a)	ALL=1;;
    A)
	notALL=true;;
    +?)
	print -ru2 -- "$name: options should not be preceded by a '+'."
	exit 1
	;;
    :) 
	print -r -u2 -- \
	"$name: Option '$OPTARG' requires a value.  Use -h for help."
	exit 1
	;;
    :) 
	print -r -u2 -- \
	"$name: Option '$OPTARG' requires a value.  Use -h for help."
	exit 1
	;;
    ?) 
	print -ru2 -- "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done
 
# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

function CheckPat {
    typeset file pattern=$1 t
    typeset -i ret=0

    [ -n "$SHELLPAT" ] && set -- $pattern || set -- "$pattern"
    for file; do
	if [ -x "$file" -a -f "$file" ]; then
	    if $listTargets; then
		print "$file"
	    else
		Files[type_i]=$file
		[ -z "$ALL" ] && return
	    fi
	    ret=1
	    let type_i+=1
	else
	    for t in $types; do
		if [ -$t "$file" ]; then
		    if $listTargets; then
			print "$file"
		    else
			Files[type_i]=$file
			[ -z "$ALL" ] && return
		    fi
		    ret=1
		    let type_i+=1
		fi
	    done
	fi
    done
    return $ret
}

# Usage: PathSearch pattern
# Sets Files[] to all files in Paths[] that match the pattern
# type_i is set to the number of matches, which is the number of elements
# put in Files[] if listTargets is false.
typeset -i type_i
function PathSearch {
    typeset arg=$1 found=false PathElem

    set +f			# make sure filename globbing is on
    unset Files
    type_i=0
    if [ -n "$SHELLPAT" -a -z "$EXACT" ]; then
	# Discard anchor chars if given, since they are not real metachars
	if [[ "$arg" = ^* ]]; then
	    arg=${arg#?}	
	else
	    arg="*$arg"	# Pattern is not anchored at start
	fi
	if [[ "$arg" = *\$ ]]; then
	    arg=${arg%?}
	else
	    arg="$arg*"	# Pattern is not anchored at end
	fi
    fi
    if [[ "$arg" = /* ]]; then
	CheckPat "$arg"
    else
	# Find all pattern matches that are executable regular files.
	for PathElem in "${Paths[@]}"; do
	    CheckPat "$PathElem/$arg"
	done
    fi
}

# This code must come after arg processing because until args are processed
# we do not know if we should read the rcfile or not.
rcFile=$HOME/$rcFile
# Let TECMD in the environment override rcfile
oTECMD=$TECMD
$Readrc && [ -f "$rcFile" ] && . $rcFile
[ -n "$oTECMD" ] && TECMD=$oTECMD
[ -z "$Cmd" -a -n "$TECMD" ] && Cmd=$TECMD

$listTargets && ALL=1
$notNOTITLE && NOTITLE=
$notVERBOSE && VERBOSE=
$notALL && ALL=
$notANYFILE && ANYFILE=
$notSYMLINKS && SYMLINKS=
$notSHELLPAT && SHELLPAT=
$notEXACT && EXACT=
[ -z "$SHELLPAT" ] && EXACT=
[ -n "$SYMLINKS" ] && types=L
[ -n "$ANYFILE" ] && types="$types f"

# $Cmd is now either a command given with -c or a default command (if any).
# If a command was given with -c, each remaining arg is a target.
# Otherwise, $1 is a comma-separated list of targets; any further arguments
# are the command and its args.

typeset -i MinArgs
# If we have a default or -c command, need only one arg (target).
# Otherwise, need at least two (list of targets and command).
[ "$name" = where -o -n "$Cmd" ] && MinArgs=1 || MinArgs=2
if [ $# -lt MinArgs ]; then
    print -ru2 "$Usage
Use -h for help."
    exit
fi

if $CmdGiven; then
    # -c given; all args are targets
    # Save targets, since the next set -A will wipe out positional params
    set -A targets -- "$@"	
    # eval this so that quoted options can be given in Cmd
    eval set -A command $Cmd
else
    # First arg is a comma-separated list of targets.
    targets=$1
    shift 1
    if [ $# -eq 0 ]; then
	# eval this so that quoted options can be given in Cmd
	eval set -A command $Cmd
    else
	set -A command "$@"
    fi
    OFS=$IFS
    IFS=,
    set -A targets -- $targets
    IFS=$OFS
fi

targList="$*"

$Debug && print -ru2 "Command: <${command[*]}>  Targets: <${targets[*]}>"

# Command & args now reside in command[]; 
# target executables are in targets[]

# If we need to get every instance of a match in the search path (ALL),
# or need to get both executable and non-executable matches (ANYFILE),
# or need to get dangling symlinks (SYMLINKS),
# or need to be able to match shell patterns (SHELLPAT),
# then we must do our own search.  Otherwise we can just use 'whence'.
if [ -n "$ALL" -o -n "$ANYFILE" -o -n "$SYMLINKS" -o -n "$SHELLPAT" ]; then
    OIFS=$IFS
    IFS=:		# Make PATH be split on :
    set -A Paths -- $PATH
    IFS=$OIFS
    LongSearch=true
else
    LongSearch=false
fi

# Get full paths to matches.
oPATH=$PATH
PATH=$searchPath
typeset -i numMatch=0
for target in "${targets[@]}"; do
    if $LongSearch; then
	PathSearch "$target"
    else
	set -A Files -- "$(whence -p $target)"	# quick search
	[ -z "$Files" ] && unset Files
	type_i=${#Files[*]}
    fi
    if [ type_i -eq 0 ]; then
	print -ru2 -- "$target: not found"
    else
	$listTargets ||
	set -A TargetExecutables -- "${TargetExecutables[@]}" "${Files[@]}"
    fi
    let numMatch+=type_i
done

PATH=$oPATH
# Quit if there were no good targets
[ numMatch -eq 0 ] && exit 1

$Debug && print -ru2 "Number of matches: $numMatch"

$listTargets && exit 0

#if $listTargets; then
#    IFS="
#"
#    print -r -- "${TargetExecutables[*]}"
#    exit 0
#fi

# Replace any {} with the list of target executables
typeset -i CmdInd=0 DestInd=0
NoAppend=false
while [ CmdInd -lt ${#command[*]} ]; do
    if [ "${command[CmdInd]}" = {} ]; then
	# Stick target args at end of cmd line being built
	set -A FullCmd -- "${FullCmd[@]}" "${TargetExecutables[@]}"
	DestInd=${#FullCmd[*]}	# Recalculate dest index
	NoAppend=true
    else
	FullCmd[DestInd]=${command[CmdInd]}
	let DestInd+=1
    fi
    let CmdInd+=1
done

$NoAppend && unset TargetExecutables[*]

if $Test; then
    print -ru2 "Would execute: ${FullCmd[@]} ${TargetExecutables[@]}"
    exit 0
fi

a0=${FullCmd[0]} 
[[ -z "$WINTITLE" || -z "$DISPLAY" || -n "$NOTITLE" || \
${a0##*/} != "${EDITOR##*/}" ]] && NOTITLE=true || NOTITLE=false

[ -n "$VERBOSE" ] && 
print -ru2 "Executing: ${FullCmd[@]} ${TargetExecutables[@]}"
$Debug && { print -ru2 "Press return to continue..."; read; }

function ResetTitle {
    print -n "\033]0;$OWINTITLE\007"
}

if $NOTITLE; then
    exec "${FullCmd[@]}" "${TargetExecutables[@]}"
else
    OWINTITLE=$WINTITLE
    # Change WINTITLE in environment, so that in case another app that
    # uses WINTITLE is run from the editor, it will use modified value
    WINTITLE="$targList ($OWINTITLE)"
    trap ResetTitle INT QUIT
    print -n "\033]0;$WINTITLE\007"      # set win title
    "${FullCmd[@]}" "${TargetExecutables[@]}"
    ResetTitle
fi