- at_bison_check_first="` \
- sed -n '/: warning: /=' at-bison-check-warnings \
- | sed -n 1p \
- `"
- at_bison_check_first_tmp="` \
- sed -n '/conflicts: [0-9].*reduce$/=' at-bison-check-warnings \
- | sed -n 1p \
- `"
+ at_bison_check_first=`sed -n \
+ '/: warning: /{=;q;}' at-bison-check-warnings`
+ : ${at_bison_check_first:=1}
+ at_bison_check_first_tmp=`sed -n \
+ '/conflicts: [0-9].*reduce$/{=;q;}' at-bison-check-warnings`
+ : ${at_bison_check_first_tmp:=1}