AWK - 296 317 321 324 334 340
Not a prize winner (yet), but I am pleased with the effort (line breaks for display). This new version uses VT-100 escape sequences. The '^[' is just one character, Escape!!! Cut and paste will not work with this version, since the sequence "^[" has to be replaced with the real ESC character. To make it forum friendly, ESC could be specified as "\0x1b", but it takes too much space...
BEGIN{FS="[ ]"}{for(j=i=0;ik?m:k}}}END{printf"^[[2J[%d;%dH+",Y=y[i=1],X=x[1];while(a=x[++i])
{a-=X;b=y[i]-Y;t=a?b?a*b>0?92:47:45:124;A=a?a>0?1:-1:0;B=b?b>0?1:-1:0;
for(r=a?a*A:b*B;--r;){printf"^[[%d;%dH%c",Y+=B,X+=A,t}
printf"^[[%d;%dH+",Y+=B,X+=A}}
The older standard version
BEGIN{FS="[ ]"}{for(j=i=0;ik?m:k}}}END{q[X=x[1],Y=y[i=1]]=43;while(a=x[++i]){a-=X;b=y[i]-Y;
t=a?b?a*b>0?92:47:45:124;A=a?a>0?1:-1:0;B=b?b>0?1:-1:0;for(r=a?a*A:b*B;--r;
q[X+=A,Y+=B]=t);q[X+=A,Y+=B]=43}for(j=0;++j
Now a little explanation
# This will break the input in fields separated by exactly 1 space,
# i.e. the fields will be null or a number.
BEGIN{FS="[ ]"}
# For each line we loop over all fields, if the field is not null
# it is a number, hence store it.
# Also account for the fact the numbers use space.
# Also, find the maximum width of the line.
{
for(j=i=0;ik?m:k
}
}
}
# Once we have all the data, let start cooking.
END{
# First, create a matrix with the drawing.
# first point is a +
q[X=x[1],Y=y[i=1]]=43;
# loop over all points
while(a=x[++i]){
# Check next point and select character
# If a == 0 -> -
# If b == 0 -> |
# If a and b have same sign -> \ else /
a-=X;b=y[i]-Y;t=a?b?a*b>0?92:47:45:124;
# there is no sgn() function
A=a?a>0?1:-1:0;B=b?b>0?1:-1:0;
# Draw the line between the points
for(k=0;++k<(a?a*A:b*B);){
q[X+=A,Y+=B]=t
}
# store + and move to next point
q[X+=A,Y+=B]=43
}
# Now output all lines. If value in point x,y is 0, emit space
for(j=0;++j
