From c6b16608718103cd46bdf1522e84edc3c0079c36 Mon Sep 17 00:00:00 2001 From: David Wells Date: Thu, 16 Dec 2021 13:02:56 -0500 Subject: [PATCH] Remove a redundant argument to xargs. On GNU, '-I {}' implies '-L 1', i.e., provide one line to each invocation. Since we are using '-0' (NUL-delimited input) we already implicitly get one item per line, so the -n 1 is redundant (and also raises a warning). A simple example: running ls --zero | xargs -0 -I {} echo 'aa {}' prints 'aa ' followed by each item in the current directory - i.e., NUL-delimited input really is represented as one line per item. --- contrib/utilities/indent_common.sh | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/contrib/utilities/indent_common.sh b/contrib/utilities/indent_common.sh index da3144581e..068c32e8bb 100644 --- a/contrib/utilities/indent_common.sh +++ b/contrib/utilities/indent_common.sh @@ -259,8 +259,8 @@ fix_permissions() export -f fix_permissions # -# Collect all files found in a list of directories "${1}$" matching a -# regular expression "${2}$", and process them with a command "${3}" on 10 +# Collect all files found in a list of directories "${1}" matching a +# regular expression "${2}", and process them with a command "${3}" on 10 # threads in parallel. # # The command line is a bit complicated, so let's discuss the more @@ -271,9 +271,9 @@ export -f fix_permissions # serves as a good candidate to separate individual file names. # - For 'xargs', -0 does the opposite: it separates filenames that are # delimited by \0 -# - the options "-n 1 -P 10" make sure that the following script will be -# called exactly with one file name as argument at a time, but we allow -# execution for up to 10 times in parallel +# - the option "-P 10" starts up to 10 processes in parallel. -0 implies '-L 1' +# (one argument to each command) so each launch of clang-format corresponds +# to exactly one file. # process() @@ -282,11 +282,11 @@ process() case "${OSTYPE}" in darwin*) find -E ${directories} -regex "${2}" -print0 | - xargs -0 -n 1 -P 10 -I {} bash -c "${3} {}" + xargs -0 -P 10 -I {} bash -c "${3} {}" ;; *) find ${directories} -regextype egrep -regex "${2}" -print0 | - xargs -0 -n 1 -P 10 -I {} bash -c "${3} {}" + xargs -0 -P 10 -I {} bash -c "${3} {}" ;; esac } @@ -318,7 +318,7 @@ process_changed() sort -u | xargs -n 1 ls -d 2>/dev/null | grep -E "^${2}$" | - ${XARGS} '\n' -n 1 -P 10 -I {} bash -c "${3} {}" + ${XARGS} '\n' -P 10 -I {} bash -c "${3} {}" } # -- 2.39.5