UNIX for Dummies Questions & Answers

Hi,
I grep for a pattern in a list of files.

"grep -i -l $pattern *.datx*"

it may give me n number of files.
say for eg, it gives me 2 files.
lock_eicu_20071228_00000000.dat_20071228_05343100
lock_eicu_20080501_00000000.dat_20080501_05343900

out of these 2 files I need to get the latest file according to the date present after the .dat extn. As 20071228 is older than 20080501, i need to get the second file.

so in the above eg, i need to get the filename
lock_eicu_20080501_00000000.dat_20080501_05343900
can u please help.

Assuming all the names are in the same format:

Code:

awk -F_ 'm<$5{m=$5;f=$0}END{print f}'

Many Thanks Frank, it works perfect.

Hi frank, one more help please,
I do below to list my files in chronological order.
ls -ltr *.datx* | tr -s ' ' | cut -d' ' -f9

it gives me list of files like below.

lock_eicu_20081120_00000000.datx_20081120_05315400
lock_eicu_20081118_00000000.datx_20081118_06303100
lock_eicu_20081111_00000001.datx_20081111_15531300
lock_eicu_20081111_00000000.datx_20081111_06335300
lock_eicu_20081030_00000000.datx_20081030_05342900
lock_eicu_20081016_00001111.datx_20081016_15525600
lock_eicu_20081016_00000000.datx_20081016_06350500
lock_eicu_20081001_00000000.datx_20081001_05344100
lock_eicu_20080912_00000000.datx_20080912_05305200
lock_eicu_20080904_00000000.datx_20080904_05335500
lock_eicu_20080822_00000000.datx_20080822_05344200
lock_eicu_20080812_00000000.datx_20080812_06331200
lock_eicu_20080808_00000000.datx_20080808_05345200
lock_eicu_20080806_00000000.datx_20080806_06343800
lock_eicu_20080802_00000000.datx_20080804_05332000
lock_eicu_20080718_00000000.datx_20080718_06533100
lock_eicu_20080606_00000000.datx_20080606_05340600
lock_eicu_20080603_00000000.datx_20080603_06345300
lock_eicu_20080531_00000000.datx_20080602_05304300
lock_eicu_20080529_00000000.datx_20080529_06330500
lock_eicu_20080501_00000000.datx_20080501_05343900
lock_eicu_20080429_00000000.datx_20080429_06311200
lock_eicu_20071228_00000000.datx_20071228_05343100

how do i sort the files again chronologically as per the date found just after .datx?
i mean in the list if u see "lock_eicu_20071228_00000000.datx_20071228_05343100" is the oldest file as it has date 20071228 after datx. so i need to list this file first and then sort so on.

Please help. Thanks again

Try:

Code:

sort -n -t_ -k5

Thanks a lot Frank. it works perfect.

hey Franklin,

care to explain the breakdown of the awk statement?

thanks