Help in locating a word in huge files

Shell Programming and Scripting
1

hi

i receive about 5000 files per day in my system. Each of them are like:

cat ABC.april24.dat
ABH00001990 01993 409009092 0909 INI iop 9033
AAB0000237893784 8430900 898383 AUS 34349089008 849843 9474822
AAA00003849893498098394 84834 348348439 -438939 IN
AAA00004438493893849384 89809 978980980 -898988 IND
.
.
.

each of these files have millions of line like this, and Each line has fix format depending upon category (ABH, AAB,AAA), i want to find all AAA category in the file which have IN any where in location 54-60, as this is invalid value and IND is correct. So like this i want to identiy all AAA lines which has invalid value 'IN' instead of 'IND'.

finding it difficult due to huge size of these files

Thanks in advance !!!

2

Not shure what output you desire but you could do something like:

awk '/^AAA/ && $NF=="IN$"{print "File: "FILENAME: ", line "FNR}' files...
3

If the lines begin with "AAA" and end with "IN" followed by optional spaces:

$ sed -n '/^AAA.*IN *$/p' ABC.april24.dat 
AAA00003849893498098394 84834 348348439 -438939 IN

Regards,
Alister