This page says that the result of the logname command and the LOGNAME variable must be the same: https://www.ibm.com/docs/en/aix/7.3?topic=l-logname-command
Thus, getlogin() implementations that use the LOGNAME or login_name variables such as musl, uclibc or even gnulib WIN32 seems fine. What to believe? Anyway, using a UID to get a login name like glibc's getlogin() function does, we sometimes get incorrect results. Here is a third test case, allowed by posix: $ cat /etc/passwd nicolas:x:1000:2001::/home/nicolas:/bin/bash claude:x:1000:2002::/home/claude:/bin/zsh localhost login: claude Password: $ echo $LOGNAME claude $ logname (glibc) nicolas $ logname (musl) claude $ logname (uclibc) claude I'm not really convinced that these fixes make things better. NB > I wrote: > > With this, coreutils should be fine, since it already imports the 'getlogin' > > module from gnulib. > > Verified by comparing coreutils-9.5 with coreutils-HEAD on Alpine Linux 3.20: > > With coreutils-9.5: > > $ logname > bruno > $ su - > Password: > # logname > root > > Now: > > $ logname > bruno > $ su - > Password: > # logname > bruno > > Paul, Pádraig: How about adding a coreutils/NEWS entry for this bug fix? > > Bruno > > > > > >
