On Fri, May 17, 2019 at 11:58 AM Bernd Petrovitsch <bernd@xxxxxxxxxxxxxxxxxxx> wrote: > > On 17/05/2019 10:16, Alexander Kapshuk wrote: > [...] > > The 'xargs' '-r' flag is a GNU extension. > > If POSIX compliance is important here, the use of 'cat', 'xargs' and > > 'basename' may be substituted with that of 'sed' to initialise > > same_name_modules: > > sed 's!.*/!!' modules.order modules.builtin | sort | uniq -d > > 's!' is TTBOMK also a GNU-extension: > sed 's/.*\///' modules.order modules.builtin | sort | uniq -d It isn't. Here's an excerpt from the POSIX manpage for 'sed', http://pubs.opengroup.org/onlinepubs/009695399/utilities/sed.html: [2addr]s/BRE/replacement/flags ... Any character other than backslash or <newline> can be used instead of a slash to delimit the BRE and the replacement.... > > > 'Sed' may also be used on its own in the 'for' loop instead of as part > > of a pipeline along with 'grep' to generate the desired output: > > sed '/\/'$m'/!d;s:^kernel/: :' modules.order modules.builtin > > sed "/\/${m}/!d;s/^kernel\// /" modules.order modules.builtin The parameter expansion syntax is redundant here. See https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_02: The parameter name or symbol can be enclosed in braces, which are optional except for positional parameters with more than one digit or when parameter is a name and is followed by a character that could be interpreted as part of the name. Here's an alternative version using double quotes. sed "/\/$m/!d;s:^kernel/: :" modules.order modules.builtin > > MfG, > Bernd > -- > Bernd Petrovitsch Email : bernd@xxxxxxxxxxxxxxxxxxx > LUGA : http://www.luga.at
