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-rwxr-xr-xtools/shpp.sh165
1 files changed, 165 insertions, 0 deletions
diff --git a/tools/shpp.sh b/tools/shpp.sh
new file mode 100755
index 0000000..c54c7b7
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+++ b/tools/shpp.sh
@@ -0,0 +1,165 @@
+#!/bin/sh
+#
+# Shell command language preprocessor
+#
+# Copyright (C) 2015 Patrick "P. J." McDermott
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+set -u
+
+VERSION='0.1.0'
+FS="$(printf '\034')"
+
+die()
+{
+ local fmt="${1}"
+ shift 1
+
+ printf "shpp: ${fmt}\n" "${@}"
+ exit 2
+}
+
+preprocess()
+{
+ local vars="${1}"
+ local input="${2}"
+ local output="${3}"
+ local def=
+ local var=
+ local val=
+
+ # Open output file.
+ if [ "x${output}" = 'x-' ]; then
+ if ! exec 3>&1; then
+ die 'Cannot duplicate output file descriptor'
+ fi
+ else
+ if ! exec 3>"${outfile}~"; then
+ die 'Cannot open file "%s"' "${output}~"
+ fi
+ fi
+
+ IFS="${FS}"
+ for def in ${vars}; do
+ case "${def}" in
+ *=*)
+ var="${def%%=*}"
+ val="${def#*=}"
+ ;;
+ *)
+ var="${def%%=*}"
+ val='true'
+ ;;
+ esac
+ case "${var}" in
+ *[!A-Za-z0-9_]*)
+ error 'Invalid variable name "%s"' "${var}"
+ continue
+ ;;
+ [0-9]*)
+ error 'Invalid variable name "%s"' "${var}"
+ continue
+ ;;
+ esac
+ printf "%s='" "${var}" >&3
+ printf '%s' "${val}" | sed "s/'/'\\\\''/g" >&3
+ printf "'\n" >&3
+ done
+ unset IFS
+
+ # Read input file.
+ if ! cat "${input}" >&3; then
+ die 'Cannot read file "%s"' "${input}"
+ fi
+
+ # Close output file, make it executable, and set its name.
+ if ! [ "x${output}" = 'x-' ]; then
+ exec 3>&-
+ if ! mv "${output}~" "${output}"; then
+ die 'Cannot rename file to "%s"' "${output}"
+ fi
+ fi
+}
+
+usage()
+{
+ printf 'Usage: %s [option ...] <infile> [<outfile>]\n' "${0}"
+}
+
+help()
+{
+ usage
+ cat <<EOF
+Options:
+ -h Display this information
+ -V Display preprocessor version information
+ -D <var>[=<val>] Predefine <var> as a variable with value <val> (default
+ "true")
+EOF
+}
+
+version()
+{
+ cat <<EOF
+shpp ${VERSION}
+Copyright (C) 2015 Patrick "P. J." McDermott
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+EOF
+}
+
+main()
+{
+ local opt=
+ local vars=
+ local infile=
+ local outfile=
+
+ while getopts 'hVD:' opt; do
+ case "${opt}" in
+ 'h')
+ help
+ exit
+ ;;
+ 'V')
+ version
+ exit
+ ;;
+ 'D')
+ vars="${vars}${OPTARG}${FS}"
+ ;;
+ esac
+ done
+ shift $(($OPTIND - 1))
+
+ case ${#} in
+ 1)
+ infile="${1}"
+ outfile='-'
+ ;;
+ 2)
+ infile="${1}"
+ outfile="${2}"
+ ;;
+ *)
+ usage >&2
+ exit 1
+ esac
+
+ preprocess "${vars}" "${infile}" "${outfile}"
+}
+
+main "${@}"