Shell Programming and Scripting

Hi,
How can I add up a series of string like:
and get a total as hour and minutes in a format like this:

All in shell...

Code:

list="1:11 0:13 2:06 1:38 1:36 0:06 0:31 0:33 0:38 0:44"

h=0
m=0
for x in ${list}
do
    h=$(( h + ${x%%:*} ))   # add hours and minutes
    m=$(( m + ${x##*:} ))
done

h=$(( h + (m /60) ))    # minutes are likely more than 60, calc hours and add in 
m=$(( m % 60 ))     # adjust minutes

echo "${h}hrs ${m}min"

To learn more...
1- Could you tell me how I can learn use of Regular Expressions?

2- Would you explain these two:
3- I get the following error for some users and for some I don't!
---------- Post updated at 09:26 PM ---------- Previous update was at 09:18 PM ----------

I fixed it. it is base 8 and I need to force bash to recognize these number as decimal by using 10# in front of the number!

Don't confuse the shell variable expansion substitution syntax with regular expressions because they are (just as confusing at first) and quite different.

For the full list of possibilities have a look at one of the shell man pages, for example the kshell page:
man/man1/ksh.html man page

The parameter expansion is about 25% down in the page (search for %% and you'll find it).

Specifically. ${name%%:*} expands the value in the variable 'name' and matches the longest pattern ":*" that is at the end of the string. The part of the expansion that is matched is truncated. So, if name contains ab:cd:ef, the expression above would match ":cd:ef" and delete that leaving just "ab".

The ${name:##*:} does the same kind of truncation, but starting from the beginning of the string. Again, if name contains "ab:cd:ef" then only "ef" would be left as the longest pattern from the beginning to ':' is "ab:cd:".

As for your error, it's treating the leading 0 as an indicator that the value should be an octal number. I don't usually work in bash -- Kshell's evaluation supports floating point calculations and doesn't make this assumption, so I wasn't aware that this would be an issue. You can compensate for this behaivour with this:

Code:

   h=$(( ${h#0} + ${x%%:*} ))  
   m=$(( ${m#0} + ${x##*:} ))

This is similar to the examples I gave above, but it matches the shortest pattern starting at the beginning of the line. So if h == "04" the expansion will just be 4, and bash won't complain. If h == "00" the expansion will be 0 which again will be fine. Finally, if h == "12" there isn't a match so there isn't a truncation.

Good luck!

---------- Post updated at 21:40 ---------- Previous update was at 21:39 ----------

Nice job!!

That happens to be a trick that I didn't know -- I approached it a bit differently, so as usual, I learned something too.