Shell Programming and Scripting

Hi-
How can I make the temporary file 0 byte , created inside gawk.

I am using
It seems system command is deleting file permanently and I am not able to execute below statement.

print ORD_HEAD_FULL >> cFILE; (cFile is temp_orders)

You should always provide the complete code. If you don't fully understand the problem, you may be omitting something important without realizing it.

Your problem is probably the result of not calling close() on that file. rm only removes the directory entry, but since AWK still has a file descriptor open on the file, the kernel will not remove it. The file still exists, although with no name in the filesystem, and AWK can continue to write to it with those print statements. Use close and then the next time you try to print to that file AWK will open (possibly creating) a new file with the same name.

Alternatively, if you only need to truncate the file, system("rm ...") is unnecessary. The following sequence will truncate:

Code:

close(cFile); printf "" > cFile

Regards,
Alister

I'm not sure I understand what you are trying to accomplish, nor what is happening, so I'm going to guess.

First, I assume that the statement:

Code:

print ORD_HEAD_FULL >> cFILE;

is in your gawk programme, and that when the gawk programme finishes you expect to have temp_orders still existing such that other functions in the script have the data that the gawk produced.

If that's correct, then don't delete the temporary file from the gawk code. Delete it at the end of the script. The short example below does this:

Code:

tmp_data=/tmp/PID$$.data1   # tempoary file for data generated by awk
ps -elf | gawk -v tdata=$tmp_data '
   /UID/ { print; next; }   # print header so it is not sorted
   { print >> tdata }       # cache data for sort later
'

sort -k 3,3 $tmp_data           # sort all non-header data
rm $tmp_data                     # remove tmp file

It's a silly example that could be done without a tmp file, but shows what I mean with regard to deleting the file at the end of the script.

Hope this helps.

---------- Post updated at 11:41 ---------- Previous update was at 11:36 ----------

After reading alister's post (we crossed), I'm not sure I made the right assumptions, but will let it stand.