问题
I'm currently writing a bash testing framework, which requires to be as portable as possible.
So, at one point, I had to print a leading newline followed by some text which contains several expanded variables. This is the solution I've used.
echo -e "\n$number_of_specs ${units}, $number_of_specs_failed failed"
This seems okay but I'm not sure how portable that is compared to printing out the line using e.g. printf
?
Any ideas or hints where I could find some references?
回答1:
printf
is more portable. It should always be preferred over echo -e
. If targeting bash/zsh/ksh specifically, echo $'...'
is also ok. If targeting zsh or ksh specifically, print
is ok.
- http://cfajohnson.com/shell/cus-faq.html#Q0b
- http://www.in-ulm.de/~mascheck/various/echo+printf/
- http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html#tag_20_37_16
POSIX (last link) also discusses echo -n
problems, which should also be avoided. Basically, never use options to echo
, and for portability, use printf.)
回答2:
The most portable (in terms of portability to ancient systems without printf) solution for leading newlines is obviously
echo
echo "$number_of_specs ${units}, $number_of_specs_failed failed"
来源:https://stackoverflow.com/questions/11530203/what-is-more-portable-echo-e-or-using-printf