2023-09-01 23:28:50 +0200, Steffen Nurpmeso via austin-group-l at The Open Group: [...] > |FWIW, a "printf %b" github shell code search returns ~ 29k > |entries > |(https://github.com/search?q=printf+%25b+language%3AShell&type=code&l=Sh\ > |ell) > | > |That likely returns only a small subset of the code that uses > |printf with %b inside the format and probably a few false > |positives, but that gives many examples of how printf %b is used > |in practice. > > Actually this returns a huge amount of false positives where > printf(1) and %b are not on the same line, let alone the same > command, if you just scroll down a bit it starts like neovim match [...]
You're right, I only looked at the first few results and saw that already gave interesting ones. Apparently, we can also search with regexps and searching for printf.*%b (https://github.com/search?q=%2Fprintf.*%25b%2F+language%3AShell&type=code) It's probably a lot more accurate. It returns ~ 19k. (still FWIW, that's still just a sample of random code on the internet) [...] > Furthermore it shows a huge amount of false use cases like > > printf >&2 "%b\n" "The following warnings and non-fatal errors were > encountered during the installation process:" [...] Yes, I also see a lot of echo -e stuff that should have been echo -E stuff (or echo alone in those (many) implementations that don't expand by default or use the more reliable printf with %s (not %b)). > It seems people think you need this to get colours mostly, which > then, it has to be said, is also practically mislead. (To the > best of *my* knowledge that is.) [...] Incidentally, ANSI terminal colour escape sequences are somewhat connecting those two %b's as they are RGB (well BGR) in binary (white is 7 = 0b111, red 0b001, green 0b010, blue 0b100), with: R=0 G=1 B=1 printf '%bcyan%b\n' "\033[3$(( 2#$B$G$R ))m" '\033[m' (with Korn-like shells, also $(( 0b$B$G$R )) in zsh though zsh has builtin colour output support including RGB-based). Speaking of stackexchange, on the June data dump of unix.stackexchange.com: stackexchange/unix.stackexchange.com$ xml2 < Posts.xml | grep -c 'printf.*%b' 494 (FWIW) Compared with %d (though that will have entries for printf(3) as well): stackexchange/unix.stackexchange.com$ xml2 < Posts.xml | grep -c 'printf.*%d' 3444 -- Stephane