backupninja/lib/parseini.in

# -*- mode: awk; indent-tabs-mode: nil; -*-
#
# parseini --- parses 'ini' style configuration files.
#
# Usage:
#   awk -f parseini S=<section> P=<param> <ini file>
#
# if section is an empty string, then we use the default section
#
# example ini file:
#
#    fruit = apple
#    fruit = pear
#    multiline = this is a multiline \
#    parameter
#
#    # this is a comment
#    [colors]
#    red = yes
#    green = no
#    blue = maybe
#
#    [ocean]
#    fish = red
#    fish = blue
#
# example usage:
#    > awk -f parseini S=ocean P=fish testfile.ini
# would return:
#    red
#    blue
#

BEGIN {
    readlines = 1
    implied = 1
}

# remove lines starting with #, but not #!
/^#[^!]/ {next}

# skip blank
/^[ \r\t]*$/ {next}

# we want to read the lines of the matched section
# and disable for other sections
/^\[.+\][ \r\t]*$/ {
    continueline = 0
    if (S && implied) {
        nline = 0
        implied = 0
    }
    if (S && match($0, "^\\[" S "\\][ \n]*")) {
        # we found the section, so start reading.
        readlines = 1
    }
    else {
        # no section, so stop reading lines
        if (readlines) readlines = 0
    }
    next
}

# when reading, store lines.

{
    if (!readlines) next
    line[nline++] = $0
    if ($0 ~ /\\[ \r\t]*$/)
        continueline = 1
    else
        continueline = 0
}

# process the read lines lines, matching parameters

END {
    # if section is set but implied is still true
    # then we never found the section, so use everything
    if (S && implied) {
        nline = 0
    }

    # if have P then find P in read lines and get values
    if (P) {
        MATCH = "^[ \r\t]*" P "[ \r\t]*="
        continueline = 0
        for (x = 0; x < nline; ++x) {
            v = line[x]
            if (continueline) {
                sub(/[ \r\t]+$/, "", v)
                if (v ~ /\\$/) {
                   v = substr(v, 1, length(v)-1)
                   sub(/[ \r\t]+$/, "", v)
                }
                if (v) value[nvalue++] = v
            }
            else if (v ~ MATCH) {
                sub(MATCH, "", v)
                sub(/^[ \r\t]+/, "", v)
                sub(/[ \r\t]+$/, "", v)
                if (v ~ /\\$/) {
                    continueline = 1
                    v = substr(v, 1, length(v)-1)
                    sub(/[ \r\t]+$/, "", v)
                }
                if (v) value[nvalue++] = v
            }
        }
        # copy parameter definition to output array
        nline = nvalue
        for (x = 0; x < nvalue; ++x)
            line[x] = value[x]
    }

    # trim all leading & trailing whitespace;
    # except for leading whitespace in continuation lines,

    for (x = 0; x < nline; ++x) {
        sub(/^[ \r\t]+/, "", line[x])
        sub(/[ \r\t]+$/, "", line[x])
    }

    # output the final result
    for (x = 0; x < nline; ++x)
        print line[x]

    if (nline) exit 0
    else exit 1
}