在Linux和AIX上使用date实用程序

Question

To verify a valid date I use the command line below:

date -d "${DATE}" "+%Y/%m/%d" > /dev/null 2>&1

It works perfectly under Cygwin, but not in my test environment. Here's some information about my test environment:

uname -a
AIX 152101a07e 3 5 00CDE2314C00

Using the command line:

echo $?

The result is always 1, even if the date is valid.

Do you have any idea why this test fails?

Answer 1

Apparently, your two environments are not running the same version of date . You should check the man page for date in your new environment (run man date ). On my machine (OS X), the -d option is used for setting daylight savings time.

For example, the following works for me :

date -j -f "%Y/%m/%d" "2014/07/09" > /dev/null 2>&1
echo $?  # 0

date -j -f "%Y/%m/%d" "2014.07.09" > /dev/null 2>&1
echo $?  # 1

-j tells it to not try to set my system date. -f means to use the specified format.

Yours may be different, but you can find out the details by reading the manual.