From: Michael Orlitzky <michael@orlitzky.com>
Date: Sun, 13 Nov 2022 00:10:19 +0000 (-0500)
Subject: utils/parse_macros: simplify and posixify.
X-Git-Tag: v0.4~8
X-Git-Url: https://gitweb.michael.orlitzky.com/?p=nagios-mode.git;a=commitdiff_plain;h=13a9ddce3994dda86585ff9435a7cbdf89f7be5f

utils/parse_macros: simplify and posixify.

Update this script to be POSIX compliant, and to run under /bin/sh
instead of /bin/bash. In addition it now prints its output to stdout
rather than a named output file, and creates its temporary file more
sanely and securely.
---

diff --git a/utils/parse_macros b/utils/parse_macros
index 186ef61..2f63b73 100755
--- a/utils/parse_macros
+++ b/utils/parse_macros
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 #
 # Parse the macro names out of Nagios' include/macros.h.
 #
@@ -8,67 +8,57 @@
 
 EXIT_USAGE=1
 EXIT_INPUT_FILE_DOESNT_EXIST=2
-EXIT_OUTPUT_FILE_EXISTS=3
-EXIT_TEMP_FILE_EXISTS=4
 
-if [ $# -lt 2 ]; then
-    echo "Usage: $0 <input_file> <output_file>"
+posix_mktemp(){
+  # Securely create a temporary file under ${TMPDIR} using the
+  # template "tmpXXXXXX", and echo the result to stdout. This works
+  # around the absence of "mktemp" in the POSIX standard.
+  printf 'mkstemp(template)' | m4 -D template="${TMPDIR:-/tmp}/tmpXXXXXX"
+}
+
+if [ $# -lt 1 ]; then
+    echo "Usage: $0 <input_file>"
     exit $EXIT_USAGE
 fi
 
 
 INFILE="$1"
 OUTFILE="$2"
-TEMPFILE="${OUTFILE}.tmp"
+TEMPFILE="$(posix_mktemp)"
 
 if [ ! -f "$INFILE" ]; then
     echo "Error: input file $INFILE doesn't exist."
     exit $EXIT_INPUT_FILE_DOESNT_EXIST
 fi
 
-if [ -f "$OUTFILE" ]; then
-    echo "Error: output file $OUTFILE already exists."
-    exit $EXIT_OUTPUT_FILE_EXISTS
-fi
-
-if [ -f "$TEMPFILE" ]; then
-    echo "Error: temporary file $TEMPFILE already exists."
-    exit $EXIT_TEMP_FILE_EXISTS
-fi
-
-# Common options. Color screws up the output.
-GREP="grep --extended-regexp --color=never"
-
-# Grep grabs all of the "#define MACRO..." lines, except for
-# MACRO_X_COUNT and MACRO_ENV_VAR_PREFIX which aren't real macros.
-# Sed just removes the "MACRO_" prefixes.
-$GREP --only-matching '[[:space:]]MACRO_[[:alnum:]_]+' "$INFILE" \
-    | $GREP -v 'MACRO_X_COUNT'                                   \
-    | $GREP -v 'MACRO_ENV_VAR_PREFIX'                            \
-    | sed 's/ MACRO_//g' >> "$OUTFILE"
+# Grabs all of the "#define MACRO..." lines, except for MACRO_X_COUNT
+# and MACRO_ENV_VAR_PREFIX which aren't real macros, and outputs the
+# macro name (everything after "MACRO_") enclosed in quotes and dollar
+# signs, appropriate to be copy/pasted directly into nagios-mode.el.
+MACRO_REGEX='#define[[:space:]]\{1,\}MACRO_\([^[:space:]]\{1,\}\)[[:space:]]\{1,\}.*'
+sed -n "s/${MACRO_REGEX}/\"\$\1\$\"/p" "${INFILE}" \
+      | sed '/X_COUNT\|ENV_VAR_PREFIX/d'           \
+      >> "${TEMPFILE}"
 
-# We need to include ARG1, ARG2... ARG<max>,
-# where the maximum is defined in macros.h.
-MAXARG=`$GREP 'MAX_COMMAND_ARGUMENTS' "$INFILE" \
-        | $GREP --only-matching '[[:digit:]]+'`
+# Add "$ARG1$", "$ARG2$",... "$ARG<max>$" to the list, where <max> is
+# defined in macros.h.
+MAXARG_REGEX='#define[[:space:]]\{1,\}MAX_COMMAND_ARGUMENTS[[:space:]]\{1,\}\([1-9][0-9]*\).*'
+MAXARG=$(sed -n "s/${MAXARG_REGEX}/\1/p" "${INFILE}")
 
 for argnum in `seq 1 $MAXARG`; do
-    echo "ARG${argnum}" >> "$OUTFILE"
+    echo "\"\$ARG${argnum}\$\"" >> "${TEMPFILE}"
 done
 
-# And, the USER1, USER2... USER<max> macros.
-# Same as above.
-MAXUSER=`$GREP 'MAX_USER_MACROS' "$INFILE" \
-         | $GREP --only-matching '[[:digit:]]+'`
+# Also the "$USER<N>$" macros, similar to the above.
+MAXUSER_REGEX='#define[[:space:]]\{1,\}MAX_USER_MACROS[[:space:]]\{1,\}\([1-9][0-9]*\).*'
+MAXUSER=$(sed -n "s/${MAXUSER_REGEX}/\1/p" "${INFILE}")
 
 for argnum in `seq 1 $MAXUSER`; do
-    echo "USER${argnum}" >> "$OUTFILE"
+    echo "\"\$USER${argnum}\$\"" >> "${TEMPFILE}"
 done
 
-# Now, we sort the thing.
-sort "$OUTFILE" > "$TEMPFILE"
+# Finally, sort the list and print it.
+sort < "${TEMPFILE}"
 
-# Add quotes and '\\$' before and after each macro. This just
-# makes it easy to cut-and-pase into nagios-mode.el.
-sed -e 's/^/\"\$/g' -e 's/$/\$\"/g' "$TEMPFILE" > "$OUTFILE"
-rm "$TEMPFILE"
+# ... and clean up
+rm "${TEMPFILE}"