Bourne Shell Case Study I

Bourne Shell Case Study I..

Case Study - Who has what??

Sometimes it is necessary to find out the difference between two files of data. We recently encountered this problem when we needed to "see" if two NT servers were in sync. We needed to know which dlls were loaded on one system and not the other. We also needed to know if the version of loaded dlls was the same.

The NT administrator created two files nts001.txt and nts002.txt that had a list of dlls. The basic layout of the files was :

$ head nts001.txt
ACCWIZ.DLL      8.0.0.3432,     11/17/96 0:00,  123392, No ,    8.0.0.3432
ACLEDIT.DLL     4.0.1381.4,     5/1/97 0:00,    135952, No ,    4.0.1381.4
ADME.DLL        1997.1.8.205,   1/11/97 23:00,  57856,  No ,    1.0.0.205
ADVAPI32.DLL    4.0.1381.4,     5/1/97 0:00,    246544, Yes,    4.0.1381.4
ALRSVC.DLL      4.0.1374.1,     8/9/96 1:30,    23312,  No ,    4.0.1374.1
AMDDLG.DLL      4.0.1371.1,     8/9/96 1:30,    9488,   No ,    4.0.1371.1
AMDNCDET.DLL    4.0.1371.1,     8/9/96 1:30,    12560,  No ,    4.0.1371.1
ASPPERF.DLL     1.0.0.0,        12/6/96 14:58,  8192,   Yes,    1.0.0.0
ASYCFILT.DLL    2.20.4118.1,    5/1/97 0:00,    118544, No ,    2.20.4118.1
AVICAP.DLL      1.15.0.1,       8/9/96 1:30,    69584,  No ,    1.15.0.1

The fields are separated by tabs, The first field is the dll name and the second is the level number. We are only interested in lines where the the dll is loaded indicated by the Yes.

The first step is to extract the "Yes" lines. This is best done with grep like:

$ grep 'Yes' Afile >Afile.l
ADVAPI32.DLL    4.0.1381.4,     5/1/97 0:00,    246544, Yes,    4.0.1381.4
ASPPERF.DLL     1.0.0.0,        12/6/96 14:58,  8192,   Yes,    1.0.0.0
AVIFIL32.DLL    4.0.1371.1,     8/9/96 1:30,    86800,  Yes,    4.0.1371.1
COMCTL32.DLL    4.70.1147.1,    5/1/97 0:00,    310032, Yes,    4.70.1147.1
COMDLG32.DLL    4.0.1381.4,     5/1/97 0:00,    185104, Yes,    4.0.1381.4
DDEML.DLL       3.50.0.103,     8/9/96 1:30,    39936,  Yes,    3.50.0.103
FTPCTRS2.DLL    4.0.1371.1,     8/9/96 1:30,    8976,   Yes,    4.0.1371.1
FTPSAPI2.DLL    4.0.1371.1,     8/9/96 1:30,    11536,  Yes,    4.0.1371.1

Now to see if the dlls in file 1 are also in file 2 we need a list of the dlls. We can get the list using cut.
```
$ dll=`cut -f1 Afile.l`
$ echo $dll | head -3
ADVAPI32.DLL 
ASPPERF.DLL 
AVIFIL32.DLL
```

Now "is an item in our dll variable list not in the second file"? To do this we need a loop to look at the entries and grep like:

for x in $dll
do
 if grep  $x $Bfile.l >/dev/null
 then
    :
 else
    grep $x $Afile.l
 fi
done


DBNMPNTW.DLL    1997.4.2.0,     6/16/97 0:00,   23552,  Yes,    6.50.2.52
GDAPI.DLL       4.0.1377.1,     8/9/96 1:30,    11024,  Yes,    4.0.1377.1

We can use this basic approach to locate items in one file not in the other file.

Now we need to find out if a dll is in both files, then is the level the the same?. Once again we will pull our list with the variable name as is 2. Then find a match in file two. Extract the version level from file1. If it is the same ok, else report the result.

sl=`cut -f1 Afile.l`
for x in $sl
do
if grep  $x Bfile.l >tmp$$
then
    v=`grep $x Afile.l | cut -f2`
    if grep $v tmp$$ >/dev/null
    then
      :
    else
     echo
     echo "Afile: " `grep $x Afile.l
     echo "Bfile: " `grep $x Bfile.l
     echo
    fi
fi
done

Putting all of the pieces together we get:

#!/bin/sh
a=$1                              # File A
b=$2                              # File B
#
# extract the loaded dlls create a .l file
#
grep 'Yes' $a >$a.l               # File A Loaded
grep 'Yes' $b >$b.l               # File B loaded
#
# find items in file A not in file B
#
echo
echo "The following DLLs are on $a but not $b"
echo
sl=`cut -f1 $a.l  `                  # get the list
for x in $sl                         # go through each item in list
do
   if grep  $x $b.l >/dev/null    # in file B?
   then
       :                             # ok do nothing
   else
       grep $x $a.l                  # not found list entry in file 1
   fi
done
#
# Now find items in file B not in file A
#
echo
echo "The following DLLs are on $b but not $a"
echo
sl=`cut -f1 $b.l  `                  # get the list
for x in $sl                         # go through each item in list
do
   if grep  $x $a.l >/dev/null    # in file A?
   then
       :                             # ok do nothing
   else
       grep $x $b.l                  # not found list entry in file 2
   fi
done
#
# Now find same dlls with differnt versions
#
echo
echo "Different versions of DLLs on $a and $b"
echo
sl=`cut -f1 $a.l`                     # get a list of dlls
for x in $sl                          # go through each item in list
do
if grep  $x $b.l >tmp$$            # Match in file B save result 
then
    v=`grep $x $a.l | cut -f2`        # get version # from file A
    if grep $v tmp$$ >/dev/null    # same as saved info?
    then
      :                               # yes do nothing
    else
     echo
     echo "$a: " `grep $x $a.l`       # no show both entries
     echo "$b: " `grep $x $b.l`
     echo
    fi
fi
done
#
# cleanup
#
rm tmp$$
rm $a.l
rm $b.l

Running this script prodcues the following:

$ diffnt nts001.txt nts002.txt

The following DLLs are on nts001.txt but not nts002.txt

HTICONS.DLL     4.0.1381.4,     5/1/97 0:00,    25360,  Yes,    4.0.1381.4

The following DLLs are on nts002.txt but not nts001.txt

DBNMPNTW.DLL    1997.4.2.0,     6/16/97 0:00,   23552,  Yes,    6.50.2.52
GDAPI.DLL       4.0.1377.1,     8/9/96 1:30,    11024,  Yes,    4.0.1377.1
GDCTRS.DLL      4.0.1377.1,     8/9/96 1:30,    9488,   Yes,    4.0.1377.1
MSVCIRT.DLL     4.20.0.6201,    8/9/96 1:30,    74752,  Yes,    4.20.0.6201
MSVCRT40.DLL    4.2000.0.6172,  8/9/96 1:30,    65024,  Yes,    4.20.0.6172
NTWDBLIB.DLL    1997.4.2.0,     6/16/97 0:00,   276480, Yes,    6.50.2.52
PRINTUI.DLL     4.0.1381.4,     5/1/97 0:00,    181520, Yes,    4.0.1381.4
SHLWAPI.DLL     4.70.0.1215,    3/22/97 12:44,  37376,  Yes,    4.70.0.1215
WINSCTRS.DLL    4.0.1371.1,     8/9/96 1:30,    10000,  Yes,    4.0.1371.1
WINSRPC.DLL     4.0.1381.3,     5/1/97 0:00,    15120,  Yes,    4.0.1381.3
WSHTCPIP.DLL    4.0.1381.4,     5/1/97 0:00,    18704,  Yes,    4.0.1381.4

Different versions of DLLs on nts001.txt and nts002.txt


nts001.txt:  MSVCRT.DLL 4.20.0.6201, 8/9/96 1:30, 267536, Yes, 4.20.0.6201
nts002.txt:  MSVCRT.DLL 5.0.0.7022, 1/22/97 23:07, 271632, Yes, 5.0.0.7022


nts001.txt:  URL.DLL 4.40.1371.1, 8/9/96 1:30, 133392, Yes, 4.40.1371.1
nts002.txt:  URL.DLL 4.70.0.1215, 3/22/97 12:44, 103184, Yes, 4.70.0.1215