I would like to highlight today's date in the output of the cal command. What is the best way?
This is what I have so far:
cal -m | grep -C6 --color "$(date +%e)"
but it doesn't work for all cases e.g, when the date has a single digit. I also want the highlighting to work when I display the calendar for a year.
I don't know how to highlight the day in the year calendar cal -y with just regular expressions, but the reason your example was not working for single digit dates is because $(date +%e) prepends a space to the output when the date has a single digit.
This will work:
cal | grep --color -EC6 "\b$(date +%e | sed "s/ //g")"
cal | grep --color -EC6 "\b"(date +%e | sed "s/ //g")
cal | grep --color -EC6 "\b$(date +%e | sed 's/ //g')\b" instead, otherwise, if the day of month is 1 or 2 there will be multiple 1x and 2x days get highlighted.
ncal -b scratched this itch for me.
On my system (openSUSE 11.4, util-linux-2.19), the current date in output form cal is automatically highlighted (reverse colors) if the output goes to terminal. As per the manpage, this seems to be the default. If it does not work on your system, it might be a bug.
cal, for example all three BSDs have different features. This isn't a bug in dogbane's cal, just a different implementation.
The output is already highlighted, so you don't need to highlight it manually. In case you want it to work with grep, you need to disable it:
cal -mh | grep -C6 --color "$(date +%e)"
cal | grep -C6 --color "\b$(date +%e)\b" ... need the boundary \b otherwise it will highlight chunks of the year too
It may be fairly complicated to do something like this;
Why not try something like pal?
I think you can use the command date +%-e instead of date +%e to remove the space.
For BSD systems without grep --color option:
B=$(tput bold)
U=$(tput sgr0)
DAY=$(date +%e | tr -d " ")
cal | sed -E -e "s|(.*[^0-9])($DAY)([^0-9].*)|\1$B\2$U\3|"
Oneliner:
cal | sed -E -e "s|(.*[^0-9])($(date +%e | tr -d " "))([^0-9].*)|\1$(tput bold)\2$(tput sgr0)\3|"
With week numbers left side:
cal -m -w | sed -E -e "s|(.*) ([[ 0-9]+])$|\2 \1|" -e "1,2s|^| |" -e "s|(.*[^0-9])($(date +%e | tr -d " "))([^0-9].*)|\1$(tput bold)\2$(tput sgr0)\3|"
cat /etc/redhat-releaseandrpm -q util-linux. This works out of the box on recent versions of Ubuntu and Fedora, so presumably you are using an old version.