tests/test-echo.sh

   1 #! /bin/sh
   2
   3 # func_exit STATUS
   4 # exit with status
   5 func_exit ()
   6 {
   7   (exit $1); exit $1
   8 }
   9
  10 # func_fatal_error message
  11 # outputs to stderr a fatal error message, and terminates the program.
  12 func_fatal_error ()
  13 {
  14   echo "test-echo.sh: *** $1" 1>&2
  15   echo "test-echo.sh: *** Stop." 1>&2
  16   func_exit 1
  17 }
  18
  19 # Ensure an 'echo' command that does not interpret backslashes.
  20 # Test cases:
  21 #   echo '\n' | wc -l                 prints 1 when OK, 2 when KO
  22 #   echo '\t' | grep t > /dev/null    has return code 0 when OK, 1 when KO
  23 # This problem is a weird heritage from SVR4. BSD got it right (except that
  24 # BSD echo interprets '-n' as an option, which is also not desirable).
  25 # Nowadays the problem occurs in 4 situations:
  26 # - in bash, when the shell option xpg_echo is set (bash >= 2.04)
  27 #            or when it was built with --enable-usg-echo-default (bash >= 2.0)
  28 #            or when it was built with DEFAULT_ECHO_TO_USG (bash < 2.0),
  29 # - in zsh, when sh-emulation is not set,
  30 # - in ksh (e.g. AIX /bin/sh and Solaris /usr/xpg4/bin/sh are ksh instances,
  31 #           and HP-UX /bin/sh and IRIX /bin/sh behave similarly),
  32 # - in Solaris /bin/sh and OSF/1 /bin/sh.
  33 # We try the following workarounds:
  34 # - for all: respawn using $CONFIG_SHELL if that is set and works.
  35 # - for bash >= 2.04: unset the shell option xpg_echo.
  36 # - for bash >= 2.0: define echo to a function that uses the printf built-in.
  37 # - for bash < 2.0: define echo to a function that uses cat of a here document.
  38 # - for zsh: turn sh-emulation on.
  39 # - for ksh: alias echo to 'print -r'.
  40 # - for ksh: alias echo to a function that uses cat of a here document.
  41 # - for Solaris /bin/sh and OSF/1 /bin/sh: respawn using /bin/ksh and rely on
  42 #   the ksh workaround.
  43 # - otherwise: respawn using /bin/sh and rely on the workarounds.
  44 # When respawning, we pass --no-reexec as first argument, so as to avoid
  45 # turning this script into a fork bomb in unlucky situations.
  46 have_echo=
  47 if echo '\t' | grep t > /dev/null; then
  48   have_echo=yes # Lucky!
  49 fi
  50 # Try the workarounds.
  51 # Respawn using $CONFIG_SHELL if that is set and works.
  52 if test -z "$have_echo" \
  53    && test "X$1" != "X--no-reexec" \
  54    && test -n "$CONFIG_SHELL" \
  55    && test -f "$CONFIG_SHELL" \
  56    && $CONFIG_SHELL -c 'echo '\t' | grep t > /dev/null'; then
  57   exec $CONFIG_SHELL "$0" --no-reexec "$@"
  58   exit 127
  59 fi
  60 # For bash >= 2.04: unset the shell option xpg_echo.
  61 if test -z "$have_echo" \
  62    && test -n "$BASH_VERSION" \
  63    && (shopt -o xpg_echo; echo '\t' | grep t > /dev/null) 2>/dev/null; then
  64   shopt -o xpg_echo
  65   have_echo=yes
  66 fi
  67 # For bash >= 2.0: define echo to a function that uses the printf built-in.
  68 # For bash < 2.0: define echo to a function that uses cat of a here document.
  69 # (There is no win in using 'printf' over 'cat' if it is not a shell built-in.)
  70 if test -z "$have_echo" \
  71    && test -n "$BASH_VERSION"; then \
  72   if type printf 2>/dev/null | grep / > /dev/null; then
  73     # 'printf' is not a shell built-in.
  74 echo ()
  75 {
  76 cat <<EOF
  77 $*
  78 EOF
  79 }
  80   else
  81     # 'printf' is a shell built-in.
  82 echo ()
  83 {
  84   printf '%s\n' "$*"
  85 }
  86   fi
  87   if echo '\t' | grep t > /dev/null; then
  88     have_echo=yes
  89   fi
  90 fi
  91 # For zsh: turn sh-emulation on.
  92 if test -z "$have_echo" \
  93    && test -n "$ZSH_VERSION" \
  94    && (emulate sh) >/dev/null 2>&1; then
  95   emulate sh
  96 fi
  97 # For ksh: alias echo to 'print -r'.
  98 if test -z "$have_echo" \
  99    && (type print) >/dev/null 2>&1; then
 100   # A 'print' command exists.
 101   if type print 2>/dev/null | grep / > /dev/null; then
 102     :
 103   else
 104     # 'print' is a shell built-in.
 105     if (print -r '\told' | grep told > /dev/null) 2>/dev/null; then
 106       # 'print' is the ksh shell built-in.
 107       alias echo='print -r'
 108     fi
 109   fi
 110 fi
 111 if test -z "$have_echo" \
 112    && echo '\t' | grep t > /dev/null; then
 113   have_echo=yes
 114 fi
 115 # For ksh: alias echo to a function that uses cat of a here document.
 116 # The ksh manual page says:
 117 #   "Aliasing is performed when scripts are read, not while they are executed.
 118 #    Therefore, for an alias to take effect, the alias definition command has
 119 #    to be executed before the command which references the alias is read."
 120 # Because of this, we have to play strange tricks with have_echo, to ensure
 121 # that the top-level statement containing the test starts after the 'alias'
 122 # command.
 123 if test -z "$have_echo"; then
 124 bsd_echo ()
 125 {
 126 cat <<EOF
 127 $*
 128 EOF
 129 }
 130 alias echo=bsd_echo 2>/dev/null
 131 fi
 132 if test -z "$have_echo" \
 133    && echo '\t' | grep t > /dev/null; then
 134   have_echo=yes
 135 fi
 136 if test -z "$have_echo"; then
 137   unalias echo 2>/dev/null
 138 fi
 139 # For Solaris /bin/sh and OSF/1 /bin/sh: respawn using /bin/ksh.
 140 if test -z "$have_echo" \
 141    && test "X$1" != "X--no-reexec" \
 142    && test -f /bin/ksh; then
 143   exec /bin/ksh "$0" --no-reexec "$@"
 144   exit 127
 145 fi
 146 # Otherwise: respawn using /bin/sh.
 147 if test -z "$have_echo" \
 148    && test "X$1" != "X--no-reexec" \
 149    && test -f /bin/sh; then
 150   exec /bin/sh "$0" --no-reexec "$@"
 151   exit 127
 152 fi
 153 if test -z "$have_echo"; then
 154   func_fatal_error "Shell does not support 'echo' correctly. Please install GNU bash and set the environment variable CONFIG_SHELL to point to it."
 155 fi
 156 if echo '\t' | grep t > /dev/null; then
 157   : # Works fine now.
 158 else
 159   func_fatal_error "Shell does not support 'echo' correctly. Workaround does not work. Please report this as a bug to bug-gnulib@gnu.org."
 160 fi
 161 if test "X$1" = "X--no-reexec"; then
 162   shift
 163 fi
 164
 165 # This command determines the exit code.
 166 echo '\t' | grep t > /dev/null