#!/bin/bash
#
# Parse the macro names out of Nagios' include/macros.h.
#
# Operates on whatever file you give it. That should probably be
# include/macros.h. Just sayin'.
#

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>"
    exit $EXIT_USAGE
fi


INFILE="$1"
OUTFILE="$2"
TEMPFILE="${OUTFILE}.tmp"

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"

# 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:]]+'`

for argnum in `seq 1 $MAXARG`; do
    echo "ARG${argnum}" >> "$OUTFILE"
done

# And, the USER1, USER2... USER<max> macros.
# Same as above.
MAXUSER=`$GREP 'MAX_USER_MACROS' "$INFILE" \
         | $GREP --only-matching '[[:digit:]]+'`

for argnum in `seq 1 $MAXUSER`; do
    echo "USER${argnum}" >> "$OUTFILE"
done

# Now, we sort the thing.
sort "$OUTFILE" > "$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"