Shell Programming and Scripting

sed '/^p\|^f\|^c\|^d\|^l/ s/^/your /' list.txt > your.txt && sed  '/^v\|^j\|^k\|^m\|^n\|^s/ s/^/the /' your.txt > the.txt && sed '/^b\|^g\|^h\|^q\|^r\|^t\|^w\|^z/ s/^/a /' the.txt > a.txt  && sed '/^a\|^e\|^i\|^o\|^u/ s/^/an /' a.txt > an.txt

an a reinforced hose
an a the non-reinforced hose

awk '
/^[pfcdl]/ {$0="your " $0; print ; next}
/^[vjkmns]/ {$0="the " $0; print ; next}
/^[bghqrtwz]/ {$0="a " $0; print ; next}
/^[aeiou]/ {$0="an " $0; print ; next}
1' list.txt

sed 's/^[aeiou]/an &/; s/^[bghqrtwz]/a &/; s/^[pfcdl]/your &/; s/^[vjkmns]/the &/ ' file
a reinforced hose
the non-reinforced hose

awk '
/^[pfcdl]/ {print "your " $0 ; next}
/^[vjkmns]/ {print "the " $0 ; next}
/^[bghqrtwz]/ {print "a " $0 ;  next}
/^[aeiou]/ {print "an " $0   ; next}
1' list.txt

/^["hour"]/ {print "an " $0 ; next}

sed 's/^\<hour\>/an &/;

/^(heir([^s]|$)|honest|honor([^s]|$)|hour([^s]|$))/{print "an " $0; next}
/^(heirs|honors|hours)/{print "the " $0; next}

/^(heir([^s]|$)|honest|honour([^s]|$)|hour([^s]|$))/{print "an " $0; next}
/^(heirs|honours|hours)/{print "the " $0; next}

an heir
an heiress
the heirs
an heirloom
the heirs' bequests
an heir's bequest
an hour
an hourly
the hours
the honors
an honorific