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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:38:56 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:38:56 +0000 |
commit | 6c20c8ed2cb9ab69a1a57ccb2b9b79969a808321 (patch) | |
tree | f63ce19d57fad3ac4a15bc26dbfbfa2b834111b5 /examples/functions/autoload | |
parent | Initial commit. (diff) | |
download | bash-upstream.tar.xz bash-upstream.zip |
Adding upstream version 5.2.15.upstream/5.2.15upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'examples/functions/autoload')
-rw-r--r-- | examples/functions/autoload | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/examples/functions/autoload b/examples/functions/autoload new file mode 100644 index 0000000..cb3a673 --- /dev/null +++ b/examples/functions/autoload @@ -0,0 +1,111 @@ +# +# An almost ksh-compatible `autoload'. A function declared as `autoload' will +# be read in from a file the same name as the function found by searching the +# $FPATH (which works the same as $PATH), then that definition will be run. +# +# To do this without source support, we define a dummy function that, when +# executed, will load the file (thereby re-defining the function), then +# execute that newly-redefined function with the original arguments. +# +# It's not identical to ksh because ksh apparently does lazy evaluation +# and looks for the file to load from only when the function is referenced. +# This one requires that the file exist when the function is declared as +# `autoload'. +# +# usage: autoload func [func...] +# +# The first cut of this was by Bill Trost, trost@reed.bitnet +# +# Chet Ramey +# chet@ins.CWRU.Edu + +# +# Declare a function ($1) to be autoloaded from a file ($2) when it is first +# called. This defines a `temporary' function that will `.' the file +# containing the real function definition, then execute that new definition with +# the arguments given to this `fake' function. The autoload function defined +# by the file and the file itself *must* be named identically. +# + +aload() +{ + eval $1 '() { . '$2' ; '$1' "$@" ; return $? ; }' +} + +# +# Search $FPATH for a file the same name as the function given as $1, and +# autoload the function from that file. There is no default $FPATH. +# + +autoload() +{ + # + # Save the list of functions; we're going to blow away the arguments + # in a second. If any of the names contain white space, TFB. + # + + local args="$*" + + # + # This should, I think, list the functions marked as autoload and not + # yet defined, but we don't have enough information to do that here. + # + if [ $# -eq 0 ] ; then + echo "usage: autoload function [function...]" >&2 + return 1 + fi + + # + # If there is no $FPATH, there is no work to be done + # + + if [ -z "$FPATH" ] ; then + echo autoload: FPATH not set or null >&2 + return 1 + fi + + # + # This treats FPATH exactly like PATH: a null field anywhere in the + # FPATH is treated the same as the current directory. + # + # The path splitting command is taken from Kernighan and Pike + # + +# fp=$(echo $FPATH | sed 's/^:/.:/ +# s/::/:.:/g +# s/:$/:./ +# s/:/ /g') + + # replaced with builtin mechanisms 2001 Oct 10 + + fp=${FPATH/#:/.:} + fp=${fp//::/:.:} + fp=${fp/%:/:.} + fp=${fp//:/ } + + for FUNC in $args ; do + # + # We're blowing away the arguments to autoload here... + # We have to; there are no arrays (well, there are, but + # this doesn't use them yet). + # + set -- $fp + + while [ $# -ne 0 ] ; do + if [ -f $1/$FUNC ] ; then + break # found it! + fi + shift + done + + if [ $# -eq 0 ] ; then + echo "$FUNC: autoload function not found" >&2 + continue + fi + +# echo auto-loading $FUNC from $1/$FUNC + aload $FUNC $1/$FUNC + done + + return 0 +} |