Eric Blake wrote:
> Since forking external programs matters most on cygwin and mingw ...
Also on AIX, HP-UX, IRIX, OSF/1, Solaris, one can avoid spawning 'cat':
by using the 'print -r' trick from libtool.m4.
2007-06-23 Bruno Haible <[EMAIL PROTECTED]>
* gnulib-tool (echo): Add a speedier workaround for ksh.
* tests/test-echo.sh: Likewise.
*** gnulib-tool 23 Jun 2007 10:14:04 -0000 1.238
--- gnulib-tool 23 Jun 2007 11:16:22 -0000
***************
*** 431,438 ****
# - for bash >= 2.0: define echo to a function that uses the printf built-in.
# - for bash < 2.0: define echo to a function that uses cat of a here
document.
# - for zsh: turn sh-emulation on.
# - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh: respawn using /bin/ksh and rely on the ksh
workaround.
# - otherwise: respawn using /bin/sh and rely on the workarounds.
# When respawning, we pass --no-reexec as first argument, so as to avoid
# turning this script into a fork bomb in unlucky situations.
--- 431,440 ----
# - for bash >= 2.0: define echo to a function that uses the printf built-in.
# - for bash < 2.0: define echo to a function that uses cat of a here
document.
# - for zsh: turn sh-emulation on.
+ # - for ksh: alias echo to 'print -r'.
# - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh and OSF/1 /bin/sh: respawn using /bin/ksh and rely on
! # the ksh workaround.
# - otherwise: respawn using /bin/sh and rely on the workarounds.
# When respawning, we pass --no-reexec as first argument, so as to avoid
# turning this script into a fork bomb in unlucky situations.
***************
*** 487,492 ****
--- 489,512 ----
&& (emulate sh) >/dev/null 2>&1; then
emulate sh
fi
+ # For ksh: alias echo to 'print -r'.
+ if test -z "$have_echo" \
+ && (type print) >/dev/null 2>&1; then
+ # A 'print' command exists.
+ if type print 2>/dev/null | grep / > /dev/null; then
+ :
+ else
+ # 'print' is a shell built-in.
+ if (print -r '\told' | grep told > /dev/null) 2>/dev/null; then
+ # 'print' is the ksh shell built-in.
+ alias echo='print -r'
+ fi
+ fi
+ fi
+ if test -z "$have_echo" \
+ && echo '\t' | grep t > /dev/null; then
+ have_echo=yes
+ fi
# For ksh: alias echo to a function that uses cat of a here document.
# The ksh manual page says:
# "Aliasing is performed when scripts are read, not while they are executed.
*** tests/test-echo.sh 23 Jun 2007 10:14:04 -0000 1.3
--- tests/test-echo.sh 23 Jun 2007 11:16:22 -0000
***************
*** 36,43 ****
# - for bash >= 2.0: define echo to a function that uses the printf built-in.
# - for bash < 2.0: define echo to a function that uses cat of a here
document.
# - for zsh: turn sh-emulation on.
# - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh: respawn using /bin/ksh and rely on the ksh
workaround.
# - otherwise: respawn using /bin/sh and rely on the workarounds.
# When respawning, we pass --no-reexec as first argument, so as to avoid
# turning this script into a fork bomb in unlucky situations.
--- 36,45 ----
# - for bash >= 2.0: define echo to a function that uses the printf built-in.
# - for bash < 2.0: define echo to a function that uses cat of a here
document.
# - for zsh: turn sh-emulation on.
+ # - for ksh: alias echo to 'print -r'.
# - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh and OSF/1 /bin/sh: respawn using /bin/ksh and rely on
! # the ksh workaround.
# - otherwise: respawn using /bin/sh and rely on the workarounds.
# When respawning, we pass --no-reexec as first argument, so as to avoid
# turning this script into a fork bomb in unlucky situations.
***************
*** 92,97 ****
--- 94,117 ----
&& (emulate sh) >/dev/null 2>&1; then
emulate sh
fi
+ # For ksh: alias echo to 'print -r'.
+ if test -z "$have_echo" \
+ && (type print) >/dev/null 2>&1; then
+ # A 'print' command exists.
+ if type print 2>/dev/null | grep / > /dev/null; then
+ :
+ else
+ # 'print' is a shell built-in.
+ if (print -r '\told' | grep told > /dev/null) 2>/dev/null; then
+ # 'print' is the ksh shell built-in.
+ alias echo='print -r'
+ fi
+ fi
+ fi
+ if test -z "$have_echo" \
+ && echo '\t' | grep t > /dev/null; then
+ have_echo=yes
+ fi
# For ksh: alias echo to a function that uses cat of a here document.
# The ksh manual page says:
# "Aliasing is performed when scripts are read, not while they are executed.
