Using a perl command within a sh script

[Belinda Dermody]

I would like to use the following perl command within a sh script is it possible.

$process_date = $date->prev;

[Mark Greene_1]

perl -e [commands]

will run the commands give from then command line or from within a shell script.

mark

[A. Clay Stephenson]

If I understand your question then
PROCESS_DATE=$(perl -e 'print scalar localtime(time() - 86400)')
echo "Process Date = ${PROCESS_DATE)"

Plan B.

PROCESS_DATE=$(caljd.sh $(caljd.sh -p 1))
echo "Process Date = ${PROCESS_DATE)"

Search Forums for caljd.sh

[A. Clay Stephenson · Accepted solution]

Ooops, that should be:
echo "Process Date = ${PROCESS_DATE}"
rather than
echo "Process Date = ${PROCESS_DATE)"

[Belinda Dermody]

Thanks Clay, I downloaded your script and once I figure it out I will add it to my program. I need the date format in yyyymmdd, the process runs at 4AM in the morning and copies a few hundred files with a datestamp of the previous day to different machines.

[Ralph Grothe]

The easiest way to do your date manipulation would be to use the solution posted by ACS, calling localtime() in scalar context.
Then you have to stick with common date format (same as date prints).
Otherwise you need to do (very little) postprocessing of the list localtime() returns in list context
(see "perldoc -f localtime")

However, your intended Perl command looks to me as if you were using some Date manipulation module (like Date::Manip or Date::Calc, or whatever) because you seem to invoke a method call on an object reference.
For this OO style to work you would need to load the module (if it's not core Perl, what I doubt), and get an object reference first.

Since I don't know what module you are using I'd use this hypothetical module Date::Magic

e.g.

PROCESS_DATE=$(perl -MDate::Magic -e 'print Date::Magic->new('now')->prev')

Of course you have to check what module you were using in your script, what the name of the constructor is, and what parameters it takes for object initialization.
grep your script for lines that have
lines with 'use' or 'require'.

So I'd think you better stick with localtime()

[H.Merijn Brand (procura]

That module already exists, and is part of my distributions:

lt09:/home/merijn 105 > perl -MDate::Manip -le'print ParseDate("yesterday")'
2004111117:21:05
lt09:/home/merijn 106 > perl -MDate::Manip -le'print ParseDate("now")'
2004111217:21:19
lt09:/home/merijn 107 >

Enjoy, Have FUN! H.Merijn

[A. Clay Stephenson]

Okay, here's the way you do that.

#!/usr/bin/sh

PROCESS_DATE=$(perl -e '($mday,$mon,$year) = (localtime(time() - 86400)) [3,4,5]; printf("%04d%02d%02d",$year + 1900,$mon + 1,$mday)')
echo "Process date = ${PROCESS_DATE}"

If I got all that typed in correctly; it should work. Note that you must add 1900 to the year and 1 to the months as localtime() returns months in the range 0-11 (as does its C counterpart); simularly years are years since 1900 CE.

Plan B:
#!/usr/bin/sh
PROCESS_DATE=$(caljd.sh -y -s $(caljd.sh -p 1))
echo "Process date = ${PROCESS_DATE}"

Invoke as caljd.sh -u for full usage and examples.