Shell Programming and Scripting

For two fields and assuming that line 1 in a file could also be your special character, you could try:

Code:

awk '
NF > 1 {if(!nf++) {
		m1 = M1 = $1
		m2 = M2 = $2
	} else {if($1 + 0 < m1)	m1 = $1
		if($1 + 0 > M1)	M1 = $1
		if($2 + 0 < m2)	m2 = $2
		if($2 + 0 > M2)	M2 = $2
	}
}
END {	print "MinColumn1 MaxColumn1 MinColumn2 MaxColumn2"
	printf("%10s %10s %10s %10s\n", m1, M1, m2, M2)
}' file

which, with your sample input produces the output:

Code:

MinColumn1 MaxColumn1 MinColumn2 MaxColumn2
 -123.7820  -119.9950    39.5520    42.0009

If you want to try this on a Solaris/SunOS system, change awk to /usr/xpg4/bin/awk.

PS. Just to be clear, the above code produces the same output if the input file is:

Code:

>
-122.2840   42.0009
-119.9950   41.1777
>
-123.7540   39.5520
-123.7820   39.6872

instead of the provided sample, while the other suggestions in this thread don't seem to produce the desired output in this case. It isn't clear to me from the provided description of the input file format whether or not this matters for the submitter's real world data.