#!/bin/sh
#
# Script is scanning system to find missing libraries
#
# Author: Adam Drzewiecki
# e-mail: A.Drzewiecki@ztpnet.pl
# Last modified: 24 July 2009
#

# Do we have sufficient privilleges?
if [ $(id -u) -ne 0 ]; then
    echo "Script \"$(basename $0)\" must be run by root."
    exit -1
fi

# List of standard searching directories
DIRECTORIES="/bin /usr/bin /usr/local/bin /sbin /usr/sbin /usr/local/sbin"
# List of missing libraries
UNAVAILABLE=""

# Add directories from PATH environment variable
for ITEM in $(echo $PATH | tr ":" " ") ; do
    # Add directory if it is not listed in DIRECTORIES
    if ! echo "$DIRECTORIES" | grep $ITEM 1>/dev/null 2>/dev/null ; then
	# Add only existing directories
	if [ -e "$ITEM" -a -d "$ITEM" ]; then
	    # Add ITEM to the comma separated DIRECTORIES list
	    if [ -z "$DIRECTORIES" ]; then
		DIRECTORIES="$ITEM"
	    else
		DIRECTORIES="$DIRECTORIES $ITEM"
	    fi
	fi
    fi
done

# Print start message
echo "Checking programs for missing library dependencies:"
echo

# For each scanned directory...
for DIRECTORY in $DIRECTORIES ; do
    echo -n "Analyzing directory $DIRECTORY: "
    
    # Find ELF executables
    EXECS=$(find $DIRECTORY | xargs file | grep "executable" | grep "ELF" | cut -f1 -d: | xargs)
    
    # Find symbolic link targets
    LINKS=$(find $DIRECTORY | xargs file | grep "symbolic link" | cut -f1 -d: | xargs)

    for LINK in $LINKS ; do
	# Find target of symbolic link
	REAL=$(readlink -e $LINK)

	# If target is a ELF executable...
	if file $REAL | grep "executable" | grep "ELF" 1>/dev/null 2>/dev/null ; then
	    
	    # ...add it to the list of tested executables
	    if ! echo $EXECS | grep $REAL 1>/dev/null 2>/dev/null ; then
		# Add REAL to the comma separated list in EXECS
		if [ -z "$EXECS" ]; then
		    EXECS="$REAL"
		else
		    EXECS="$EXECS $REAL"
		fi
	    fi
	fi
    done
    
    # Before the first found missing library scanned directory is OK
    FAILED="0"
    
    # For each tested executables...
    for EXEC in $EXECS; do
    
	# Find missing libraries
	MISSING=$(ldd $EXEC | grep "not found" | cut -f1 -d" " | sort | uniq | xargs)

	# If there are any missing libraries
	if [ -n "$MISSING" ] ; then

	    # Mark directory as tainted	    
	    if [ $FAILED == "0" ]; then
		echo "FAILED"
		echo
		
		FAILED="1"
	    fi

	    # Print message
	    echo "Program $EXEC is missing following libraries: $MISSING"
	    
	    # Add each misisng libraries to the list...
	    for LIB in $MISSING; do
		# ...if it isn't recorded yet
		if ! echo "$UNAVAILABLE" | grep $LIB 1>/dev/null 2>/dev/null ; then
		    # Add LIB to the comma separated list in UNAVAILABLE
		    if [ -z "$UNAVAILABLE" ]; then
			UNAVAILABLE="$LIB"
		    else
			UNAVAILABLE="$UNAVAILABLE $LIB"
		    fi
		fi
	    done
	fi
    done    

    # Print newline after each directory with missing libraries
    if [ "$FAILED" == "0" ]; then
	echo "OK"
    else
	echo
    fi
done

# If missing libraries list is empty...
if [ -z "$UNAVAILABLE" ]; then
    # ...print OK message and return 0...
    echo
    echo "System has all necessary libraries."
    exit 0
else
    # ...else print list of missing libraries and return 1
    echo
    echo "List of missing libraries: $UNAVAILABLE"
    exit 1
fi