#
# from: @(#)math.sed 8.1 (Berkeley) 6/6/93
# $NetBSD: math.sed,v 1.3 1997/01/09 20:21:36 tls Exp $
#
# Addition and multiplication in sed.
# ++ for a limited time only do (expr) too!!!
#
# Kevin S Braunsdorf, PUCC UNIX Group,
[email protected].
#
# Ex:
# echo "4+7*3" | sed -f %f
# make sure the expression is well formed
s/[ ]//g
/[+*\/-]$/{
a\
poorly formed expression, operator on the end
q
}
/^[+*\/]/{
a\
poorly formed expression, leading operator
q
}
# fill hold space with done token
x
s/^.*/done/
x
# main loop, process operators (*, + and () )
: loop
/^\+/{
s///
b loop
}
/^\(.*\)(\([^)]*\))\(.*\)$/{
H
s//\2/
x
s/^\(.*\)\n\(.*\)(\([^()]*\))\(.*\)$/()\2@\4@\1/
x
b loop
}
/^[0-9]*\*/b mul
/^\([0-9]*\)\+\([0-9+*]*\*[0-9]*\)$/{
s//\2+\1/
b loop
}
/^[0-9]*\+/{
s/$/=/
b add
}
x
/^done$/{
x
p
d
}
/^()/{
s///
x
G
s/\(.*\)\n\([^@]*\)@\([^@]*\)@\(.*\)/\2\1\3/
x
s/[^@]*@[^@]*@\(.*\)/\1/
x
b loop
}
i\
help, stack problem
p
x
p
q
# turn mul into add until 1*x -> x
: mul
/^0*1\*/{
s///
b loop
}
/^\([0-9]*\)0\*/{
s/^\([0-9]*\)0\*\([0-9]*\)/\1*\20/
b mul
}
s/^\([0-9]*\)1\*/\10*/
s/^\([0-9]*\)2\*/\11*/
s/^\([0-9]*\)3\*/\12*/
s/^\([0-9]*\)4\*/\13*/
s/^\([0-9]*\)5\*/\14*/
s/^\([0-9]*\)6\*/\15*/
s/^\([0-9]*\)7\*/\16*/
s/^\([0-9]*\)8\*/\17*/
s/^\([0-9]*\)9\*/\18*/
s/\*\([0-9*]*\)/*\1+\1/
b mul
# get rid of a plus term until 0+x -> x
: add
/^\+\([0-9+*]*\)=/{
s//\1/
b loop
}
/^\([0-9*]*\)\+=/{
s//\1/
b loop
}
/^\([0-9]*\)\+\([0-9*+]*\)\+=/{
s//\2+\1/
b loop
}
/^\([0-9]*\)0\+\([0-9]*\)\([0-9]\)=/{
s//\1+\2=\3/
b add
}
/^\([0-9]*\)\([0-9]\)\+\([0-9]*\)0=/{
s//\1+\3=\2/
b add
}
/^\([0-9]*\)0\+\([0-9*+]*\)\+\([0-9]*\)\([0-9]\)=/{
s//\1+\2+\3=\4/
b add
}
/^\([0-9]*\)\([0-9]\)\+\([0-9*+]*\)\+\([0-9]*\)0=/{
s//\1+\3+\4=\2/
b add
}
s/^\([0-9]*\)1\+/\10+/
s/^\([0-9]*\)2\+/\11+/
s/^\([0-9]*\)3\+/\12+/
s/^\([0-9]*\)4\+/\13+/
s/^\([0-9]*\)5\+/\14+/
s/^\([0-9]*\)6\+/\15+/
s/^\([0-9]*\)7\+/\16+/
s/^\([0-9]*\)8\+/\17+/
s/^\([0-9]*\)9\+/\18+/
s/9=\([0-9]*\)$/_=\1/
s/8=\([0-9]*\)$/9=\1/
s/7=\([0-9]*\)$/8=\1/
s/6=\([0-9]*\)$/7=\1/
s/5=\([0-9]*\)$/6=\1/
s/4=\([0-9]*\)$/5=\1/
s/3=\([0-9]*\)$/4=\1/
s/2=\([0-9]*\)$/3=\1/
s/1=\([0-9]*\)$/2=\1/
/_/{
s//_0/
: inc
s/9_/_0/
s/8_/9/
s/7_/8/
s/6_/7/
s/5_/6/
s/4_/5/
s/3_/4/
s/2_/3/
s/1_/2/
s/0_/1/
s/\+_/+1/
/_/b inc
}
b add
