tests/misc/stdbuf.sh

   1 #!/bin/sh
   2 # Exercise stdbuf functionality
   3
   4 # Copyright (C) 2009-2024 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  20 print_ver_ stdbuf env
  21
  22 getlimits_
  23
  24 # stdbuf fails when the absolute top build dir name contains e.g.,
  25 # space, TAB, NL
  26 lf='
  27 '
  28 case $abs_top_builddir in
  29   *[\\\"\#\$\&\'\`$lf\ \        ]*)
  30     skip_ "unsafe absolute build directory name: $abs_top_builddir";;
  31 esac
  32
  33 # Use a fifo rather than a pipe in the tests below
  34 # so that the producer (uniq) will wait until the
  35 # consumer (dd) opens the fifo therefore increasing
  36 # the chance that dd will read the data from each
  37 # write separately.
  38 mkfifo_or_skip_ fifo
  39
  40
  41 # Verify input parameter checking
  42 stdbuf -o1 true || fail=1 # verify size syntax
  43 stdbuf -oK true || fail=1 # verify size syntax
  44 stdbuf -o0 true || fail=1 # verify unbuffered syntax
  45 stdbuf -oL true || fail=1 # verify line buffered syntax
  46
  47 # Capital 'L' required
  48 # Internal error is a particular status
  49 returns_ 125 stdbuf -ol true || fail=1
  50
  51 returns_ 125 stdbuf -o$SIZE_OFLOW true || fail=1 # size too large
  52 returns_ 125 stdbuf -iL true || fail=1 # line buffering stdin disallowed
  53 returns_ 125 stdbuf true || fail=1 # a buffering mode must be specified
  54 stdbuf -i0 -o0 -e0 true || fail=1 #check all files
  55 returns_ 126 env . && { returns_ 126 stdbuf -o1 . || fail=1; } # invalid command
  56 returns_ 127 stdbuf -o1 no_such || fail=1 # no such command
  57
  58 # Terminate any background processes
  59 cleanup_() { kill $pid 2>/dev/null && wait $pid; }
  60
  61 # Ensure line buffering stdout takes effect
  62 stdbuf_linebuffer()
  63 {
  64   local delay="$1"
  65
  66   printf '1\n' > exp
  67   > out || framework_failure_
  68   dd count=1 if=fifo > out 2> err & pid=$!
  69   (printf '1\n'; sleep $delay; printf '2\n') | stdbuf -oL uniq > fifo
  70   wait $pid
  71   compare exp out
  72 }
  73
  74 retry_delay_ stdbuf_linebuffer .1 6 || fail=1
  75
  76 stdbuf_unbuffer()
  77 {
  78   local delay="$1"
  79
  80   # Ensure un buffering stdout takes effect
  81   printf '1\n' > exp
  82   > out || framework_failure_
  83   dd count=1 if=fifo > out 2> err & pid=$!
  84   (printf '1\n'; sleep $delay; printf '2\n') | stdbuf -o0 uniq > fifo
  85   wait $pid
  86   compare exp out
  87 }
  88
  89 retry_delay_ stdbuf_unbuffer .1 6 || fail=1
  90
  91 # Ensure un buffering stdin takes effect
  92 #  The following works for me, but is racy.  I.e., we're depending
  93 #  on dd to run and close the fifo before the second write by uniq.
  94 #  If we add a sleep, then we're just testing -oL
  95     # printf '3\n' > exp
  96     # dd count=1 if=fifo > /dev/null 2> err &
  97     # printf '1\n\2\n3\n' | (stdbuf -i0 -oL uniq > fifo; cat) > out
  98     # wait # for dd to complete
  99     # compare exp out || fail=1
 100 #  One could remove the need for dd (used to close the fifo to get uniq to quit
 101 #  early), if head -n1 read stdin char by char. Note uniq | head -c2 doesn't
 102 #  suffice due to the buffering implicit in the pipe.  sed currently does read
 103 #  stdin char by char, so we can test with 'sed 1q'.  However I'm wary about
 104 #  adding this dependency on a program outside of coreutils.
 105     # printf '2\n' > exp
 106     # printf '1\n2\n' | (stdbuf -i0 sed 1q >/dev/null; cat) > out
 107     # compare exp out || fail=1
 108
 109 # Ensure block buffering stdout takes effect
 110 # We don't currently test block buffering failures as
 111 # this doesn't work on GLIBC-2.7 or GLIBC-2.9 at least.
 112    # stdbuf_blockbuffer()
 113    # {
 114    #   local delay="$1"
 115    #
 116    #   printf '1\n2\n' > exp
 117    #   dd count=1 if=fifo > out 2> err &
 118    #   (printf '1\n'; sleep $delay; printf '2\n') | stdbuf -o4 uniq > fifo
 119    #   wait # for dd to complete
 120    #   compare exp out
 121    # }
 122    #
 123    # retry_delay_ stdbuf_blockbuffer .1 6 || fail=1
 124
 125 Exit $fail