diff should handle headers just fine, sothis file contains a few lines of headerand footer, with a couple of false starts,consisting of lines starting with--- some wordsbut no immediately following +++ wordslines --- header.in+++ header.out@@ -1,3 +1,5 @@+1+2 3 4 5@@ -10,8 +12,8 @@ 12 13 14-13-12+15+16 17 18 19@@ -35,6 +37,8 @@ 37 38 39+40+41 42 43 44@@ -80,6 +84,7 @@ 84 85 86+87 88 89 90@@ -91,3 +96,5 @@ 96 97 98+99+100-- signature footer: should not get picked upand here is the footer that shouldalso be ignored.