mzs

  $ what /usr/bin/file
  /usr/bin/file:
   PROGRAM:file  PROJECT:file-106
   $File: apprentice.c,v 1.309 2021/09/24 13:59:19 christos Exp $
   $File: apptype.c,v 1.14 2018/09/09 20:33:28 christos Exp $
   $File: ascmagic.c,v 1.109 2021/02/05 23:01:40 christos Exp $
   $File: buffer.c,v 1.8 2020/02/16 15:52:49 christos Exp $
   $File: cdf_time.c,v 1.19 2019/03/12 20:43:05 christos Exp $
   $File: cdf.c,v 1.120 2021/09/24 13:59:19 christos Exp $
   $File: compress.c,v 1.129 2020/12/08 21:26:00 christos Exp $
   $File: der.c,v 1.21 2020/06/15 00:58:10 christos Exp $
   $File: encoding.c,v 1.32 2021/04/27 19:37:14 christos Exp $
   $File: fsmagic.c,v 1.81 2019/07/16 13:30:32 christos Exp $
   $File: funcs.c,v 1.122 2021/06/30 10:08:48 christos Exp $
   $File: is_csv.c,v 1.6 2020/08/09 16:43:36 christos Exp $
   $File: is_json.c,v 1.15 2020/06/07 19:05:47 christos Exp $
   $File: is_tar.c,v 1.44 2019/02/20 02:35:27 christos Exp $
   $File: magic.c,v 1.115 2021/09/20 17:45:41 christos Exp $
   $File: print.c,v 1.89 2021/06/30 10:08:48 christos Exp $
   $File: readcdf.c,v 1.74 2019/09/11 15:46:30 christos Exp $
   $File: readelf.c,v 1.178 2021/06/30 10:08:48 christos Exp $
   $File: softmagic.c,v 1.315 2021/09/03 13:17:52 christos Exp $
   $File: file.c,v 1.190 2021/09/24 14:14:26 christos Exp $
  ...
 
  WHAT(1)                     General Commands Manual                    WHAT(1)
  
  NAME
       what - show what versions of object modules were used to construct a file
  
  SYNOPSIS
       what [-qs] [file ...]
  
  DESCRIPTION
       The what utility searches each specified file for sequences of the form
       "@(#)" as inserted by the SCCS source code control system.  It prints the
       remainder of the string following this marker, up to a NUL character,
       newline, double quote, `>' character, or backslash.
  
       The following options are available:
  
       -q      Only output the match text, rather than formatting it.
  
       -s      Stop searching each file after the first match.
  
  EXIT STATUS
       Exit status is 0 if any matches were found, otherwise 1.
  
  SEE ALSO
       ident(1), strings(1)
  
  STANDARDS
       The what utility conforms to IEEE Std 1003.1-2001 ("POSIX.1").  The -q
       option is a non-standard FreeBSD extension which may not be available on
       other operating systems.
  
  HISTORY
       The what command appeared in 4.0BSD.
  
  BUGS
       This is a rewrite of the SCCS command of the same name, and behavior may
       not be identical.
  
  macOS 26.4                     December 14, 2006                    macOS 26.4

  $ {
  >     echo foo \
  >     && echo bar \
  >     || echo baz ;
  > }
  foo
  bar
  <^P><^A>$<^F>IFS
  ${IFS#   echo foo   && echo bar   || echo baz ; }
  $ _

  $ foo |
    bar | # ?Do? *the* $bar$ && [do] {it!}
    baz

  <^P>
  $ foo |   bar | # ?Do? *the* $bar$ && [do] {it!}
  baz

  $ echo foo | tr fo FO | sed 's/FOO/BAR/'
  BAR
  $ echo foo | ${IFS# tr fo FO | } sed 's/FOO/BAR/'
  foo

  foo \
  | bar ${IFS Do the bar. Do it. } \
  | baz

  controlling terminal
  session leader
  job control

  -> ioTaskStdGet 0, 1
  value = 3 = 0x3
  -> taskIdSelf
  value = 13600784 = 0xcf8810

  -> ioTaskStdSet 0xcf8810, 1, 0x9
  value = 0 = 0x0

  -> printf "foo\n"
  -> taskIdSelf
  -> i

  -> foo
  value = 4 = 0x4
  value = 13600784 = 0xcf8810


     NAME         ENTRY       TID    PRI   STATUS      PC       SP     ERRNO  DELAY
  ----------  ------------ -------- --- ---------- -------- -------- ------- -----
  ...