Shell Programming and Scripting

To make it simply clear:

for file in *_*_*.dat won't match any of your files. Try *_*.*.dat instead.

FILESTAMP=${file#*_} will result in 20171204.052389.dat if $file contains abc_20171204.052389.dat

FILESTAMP=${FILESTAMP%%.*} will yield 20171204 from above. Watch the double %% sign, and the . in lieu of _ .

From your perpetuating identical questions I don't get the feeling you tried any analysing / understanding of the proposal you were given.

thank you. I ran the whole script .

Code:

output in the other file has 
"Binary file abc_20171204.052389.dat matches"

Script is not coping the contents that has 'GENERIC' to other file.

It looks like your file has some characters that are non-text and grep is assuming the file is binary.

You can force grep to treat your file as text with the -a option:

eg: replace your grep command in the script as follows:

Code:

       if [ $? -eq 1 ] 
       then
           # copy all data that has GENERIC to "other file"
           grep -a "GENERIC" $file >> ./"other file"
       fi

Thank you it worked and successfully created a file.


If we have multiple files in the directory which has text

Code:

'S A M P L E'

in the files starting at

Code:

position 31 on line 19

.What will happen?Will script picks the latest file and process it and than exits?Please guide.

Note that if your *.dat files are not true text files (i.e., no lines longer than 2048 bytes including the terminating <newline> character, every line is terminated by a <newline> character, and contains no NUL characters), the awk script you're using may give you false negatives. If, as an example, each of your "lines" starts with a single 4-byte binary integer value, each of those four bytes could be misinterpreted by awk as a <newline> character. So, in this example, it is theoretically possible that the string S A M P L E might appear on what appears to awk to be any line between line 31 and line 155 in position 27, 28, 29, 30, or 31.

If we knew what operating system you're using, what shell you're using, and the actual format of the .dat files that are being processed by your script; there might be a way to write a shell script, an awk script, or a C program to reliably search those files for the strings you want to find.

The current form of the script will take all files that match your specified requirement (timestamp within 3 days and containing SAMPLE text) and extract the GENERIC text from them all this is appended to the 'other file'

Hi Chublar,

Thank you!My requirement is to pick and process the latest file received in past 3 days, which has 'SAMPLE' in position 31 on line 19 and than grep 'GENERIC' in the file and copying it to other file.


Instead of appending the 'GENERIC' text from all the files.Can we just only process the latest file which has 'SAMPLE' ?


operating system is windows 7 32 bit.
shell: /bin/bash
.dat file is : fixed width