What does ">!" do in bash or nawk?

Question

I am translating a GAWK script into a C# program and I don't know what part of the GAWK script means. I've got the rest of the script figured out but I can't seem to find where to look for the rest of these commands.

I don't have an example of the other .tg files that its reading so I'm copying it blind and I need to get it right.

These are the lines:

date +"Report prepared %a %b %e %T %Y" >! $XTRAFILE
set ntg=`awk '\!/^#/{if(NF)print}' *.tg ad_tgs | wc -l`

Questions:

Am I right in assuming that it puts the ">!" puts the "Report prepared" at the top of the $XTRAFILE?
Also, I don't know what the "%a %b %e ..." is.
Finally, is the line starting with "set ntg" counting the lines in the ad_tgs file?

In the future, if you have questions about GAWK itself, I'd suggest using [Unix Stack Exchange](http://unix.stackexchange.com/questions/tagged/gawk). — Dragomok, Feb 20 '17 at 18:06
@Dragomok - why would you suggest that? Seems like a lot of awk or gawk questions get answered right here and if you really need experts then you should post in the comp.lang.awk newsgroup. — Ed Morton, Feb 20 '17 at 20:24
@jas Thanks for the link. I searched for ">!" before I asked but nothing came up. — Kaden.Goodell, Feb 20 '17 at 23:59
@EdMorton I meant no negative intent - just that Unix SE *might* have a bigger crowd of readily available answerers. — Dragomok, Feb 21 '17 at 17:52

score 5 · Accepted Answer · edited Feb 22 '23 at 02:54

Am I right in assuming that it puts the ">!" puts the "Report prepared" at the top of the $XTRAFILE?

>! came from csh and tcsh, will write stdout to file, overwriting any existing file

Read More Here
Also, I don't know what the "%a %b %e ..." is.

%a locale's abbreviated weekday name (e.g., Sun)

%b locale's abbreviated month name (e.g., Jan)

%e day of month, space padded; same as %_d

%T time; same as %H:%M:%S

%Y year

Read more Here
Finally, is the line starting with "set ntg" counting the lines in the ad_tgs file?
```
  set ntg=`awk '\!/^#/{if(NF)print}' *.tg ad_tgs | wc -l`
```
Prints all records/rows, which does not start with char # and has at least 1 field from all files, whos extension is .tg and file ad_tgs and | wc -l count number of lines which awk printed, and finally store number of lines in variable ntg

What does ">!" do in bash or nawk?

1 Answers1