manweb: A CGI script to display man pages

This function takes the page name and section, builds a full absolute path name, and checks that the file exists.

# - - -   f i n d M a n F i l e

def findManFile ( pageName, section, suffix ):
    """Locate the man page and verify its existence.

      [ (pageName is a page name as a string) and
        (section is a section number as a string) and
        (suffix is a suffix string) ->
          if that man page exists in that section ->
            return the absolute path to the page
          else ->
            sys.stdout  +:=  an error message as HTML
            stop execution ]
    """

First build the absolute pathname to the file. Then see if the file exists. See Section 4.4.1, “MAN_BASE” for the constant that defines the path to the top directory of the man page structure.

    #-- 1 --
    # [ manPath  :=  path to the man file for page name
    #       (pageName), section (section), and suffix (suffix) ]
    manPath  =  ( "%s%s/%s.%s%s.gz" %
                  (MAN_BASE, section, pageName, section, suffix) )
    #-- 2 --
    # [ if manPath names an existing file ->
    #     I
    #   else ->
    #     sys.stdout  +:=  an error message in HTML
    #     stop execution ]
    if  not os.path.exists ( manPath ):
        errorPage ( "No such man page: %s" % manPath )

    #-- 3 --
    return manPath