by hand

by hand adv.  1. Said of an operation (especially a
   repetitive, trivial, and/or tedious one) that ought to be performed
   automatically by the computer, but which a hacker instead has to
   step tediously through.  "My mailer doesn't have a command to
   include the text of the message I'm replying to, so I have to do it
   by hand."  This does not necessarily mean the speaker has to
   retype a copy of the message; it might refer to, say, dropping into
   a subshell from the mailer, making a copy of one's mailbox file,
   reading that into an editor, locating the top and bottom of the
   message in question, deleting the rest of the file, inserting `>'
   characters on each line, writing the file, leaving the editor,
   returning to the mailer, reading the file in, and later remembering
   to delete the file.  Compare {eyeball search}.  2. By extension,
   writing code which does something in an explicit or low-level way
   for which a presupplied library routine ought to have been
   available.  "This cretinous B-tree library doesn't supply a decent
   iterator, so I'm having to walk the trees by hand."