From Wikibooks, open books for an open world
v1.0 / 11 mar 90 / gvg v1.1 / 29 nov 94 / gvg / Cosmetic rewrite. v1.2 / 12 oct 95 / gvg / Web rewrite, added stuff on shell scripts. v1.3 / 15 jan 99 / gvg / Minor cosmetic update. v1.0.4 / 01 jan 02 / gvg / Minor cosmetic update. v1.0.5 / 01 jan 04 / gvg / Minor cosmetic update. v1.0.6 / 01 may 04 / gvg / Added comments on state variables. v1.0.7 / 01 jun 04 / gvg / Added comments on numeric / string comparisons. v1.0.8 / 01 jul 04 / gvg / Corrected an obnoxious typo error. v1.0.9 / 01 oct 04 / gvg / Corrected another tweaky error. v1.1.0 / 01 sep 06 / gvg / Minor update, changed title to "Primer". v1.1.1 / 01 aug 08 / gvg / Minor cosmetic update.
