new file mode 100755
@@ -0,0 +1,446 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: Apache-2.0
+
+set -o errexit -o nounset -o pipefail
+
+NAT='0|[1-9][0-9]*'
+ALPHANUM='[0-9]*[A-Za-z-][0-9A-Za-z-]*'
+IDENT="$NAT|$ALPHANUM"
+FIELD='[0-9A-Za-z-]+'
+
+SEMVER_REGEX="\
+^[vV]?\
+($NAT)\\.($NAT)\\.($NAT)\
+(\\-(${IDENT})(\\.(${IDENT}))*)?\
+(\\+${FIELD}(\\.${FIELD})*)?$"
+
+PROG=semver
+PROG_VERSION="3.4.0"
+
+USAGE="\
+Usage:
+ $PROG bump major <version>
+ $PROG bump minor <version>
+ $PROG bump patch <version>
+ $PROG bump prerel|prerelease [<prerel>] <version>
+ $PROG bump build <build> <version>
+ $PROG bump release <version>
+ $PROG get major <version>
+ $PROG get minor <version>
+ $PROG get patch <version>
+ $PROG get prerel|prerelease <version>
+ $PROG get build <version>
+ $PROG get release <version>
+ $PROG compare <version> <other_version>
+ $PROG diff <version> <other_version>
+ $PROG validate <version>
+ $PROG --help
+ $PROG --version
+
+Arguments:
+ <version> A version must match the following regular expression:
+ \"${SEMVER_REGEX}\"
+ In English:
+ -- The version must match X.Y.Z[-PRERELEASE][+BUILD]
+ where X, Y and Z are non-negative integers.
+ -- PRERELEASE is a dot separated sequence of non-negative integers and/or
+ identifiers composed of alphanumeric characters and hyphens (with
+ at least one non-digit). Numeric identifiers must not have leading
+ zeros. A hyphen (\"-\") introduces this optional part.
+ -- BUILD is a dot separated sequence of identifiers composed of alphanumeric
+ characters and hyphens. A plus (\"+\") introduces this optional part.
+
+ <other_version> See <version> definition.
+
+ <prerel> A string as defined by PRERELEASE above. Or, it can be a PRERELEASE
+ prototype string followed by a dot.
+
+ <build> A string as defined by BUILD above.
+
+Options:
+ -v, --version Print the version of this tool.
+ -h, --help Print this help message.
+
+Commands:
+ bump Bump by one of major, minor, patch; zeroing or removing
+ subsequent parts. \"bump prerel\" (or its synonym \"bump prerelease\")
+ sets the PRERELEASE part and removes any BUILD part. A trailing dot
+ in the <prerel> argument introduces an incrementing numeric field
+ which is added or bumped. If no <prerel> argument is provided, an
+ incrementing numeric field is introduced/bumped. \"bump build\" sets
+ the BUILD part. \"bump release\" removes any PRERELEASE or BUILD parts.
+ The bumped version is written to stdout.
+
+ get Extract given part of <version>, where part is one of major, minor,
+ patch, prerel (alternatively: prerelease), build, or release.
+
+ compare Compare <version> with <other_version>, output to stdout the
+ following values: -1 if <other_version> is newer, 0 if equal, 1 if
+ older. The BUILD part is not used in comparisons.
+
+ diff Compare <version> with <other_version>, output to stdout the
+ difference between two versions by the release type (MAJOR, MINOR,
+ PATCH, PRERELEASE, BUILD).
+
+ validate Validate if <version> follows the SEMVER pattern (see <version>
+ definition). Print 'valid' to stdout if the version is valid, otherwise
+ print 'invalid'.
+
+See also:
+ https://semver.org -- Semantic Versioning 2.0.0"
+
+function error {
+ echo -e "$1" >&2
+ exit 1
+}
+
+function usage_help {
+ error "$USAGE"
+}
+
+function usage_version {
+ echo -e "${PROG}: $PROG_VERSION"
+ exit 0
+}
+
+# normalize the "part" keywords to a canonical string. At present,
+# only "prerelease" is normalized to "prerel".
+
+function normalize_part {
+ if [ "$1" == "prerelease" ]
+ then
+ echo "prerel"
+ else
+ echo "$1"
+ fi
+}
+
+function validate_version {
+ local version=$1
+ if [[ "$version" =~ $SEMVER_REGEX ]]; then
+ # if a second argument is passed, store the result in var named by $2
+ if [ "$#" -eq "2" ]; then
+ local major=${BASH_REMATCH[1]}
+ local minor=${BASH_REMATCH[2]}
+ local patch=${BASH_REMATCH[3]}
+ local prere=${BASH_REMATCH[4]}
+ local build=${BASH_REMATCH[8]}
+ eval "$2=(\"$major\" \"$minor\" \"$patch\" \"$prere\" \"$build\")"
+ else
+ echo "$version"
+ fi
+ else
+ error "version $version does not match the semver scheme 'X.Y.Z(-PRERELEASE)(+BUILD)'. See help for more information."
+ fi
+}
+
+function is_nat {
+ [[ "$1" =~ ^($NAT)$ ]]
+}
+
+function is_null {
+ [ -z "$1" ]
+}
+
+function order_nat {
+ [ "$1" -lt "$2" ] && { echo -1 ; return ; }
+ [ "$1" -gt "$2" ] && { echo 1 ; return ; }
+ echo 0
+}
+
+function order_string {
+ [[ $1 < $2 ]] && { echo -1 ; return ; }
+ [[ $1 > $2 ]] && { echo 1 ; return ; }
+ echo 0
+}
+
+# given two (named) arrays containing NAT and/or ALPHANUM fields, compare them
+# one by one according to semver 2.0.0 spec. Return -1, 0, 1 if left array ($1)
+# is less-than, equal, or greater-than the right array ($2). The longer array
+# is considered greater-than the shorter if the shorter is a prefix of the longer.
+#
+function compare_fields {
+ local l="$1[@]"
+ local r="$2[@]"
+ local leftfield=( "${!l}" )
+ local rightfield=( "${!r}" )
+ local left
+ local right
+
+ local i=$(( -1 ))
+ local order=$(( 0 ))
+
+ while true
+ do
+ [ $order -ne 0 ] && { echo $order ; return ; }
+
+ : $(( i++ ))
+ left="${leftfield[$i]}"
+ right="${rightfield[$i]}"
+
+ is_null "$left" && is_null "$right" && { echo 0 ; return ; }
+ is_null "$left" && { echo -1 ; return ; }
+ is_null "$right" && { echo 1 ; return ; }
+
+ is_nat "$left" && is_nat "$right" && { order=$(order_nat "$left" "$right") ; continue ; }
+ is_nat "$left" && { echo -1 ; return ; }
+ is_nat "$right" && { echo 1 ; return ; }
+ { order=$(order_string "$left" "$right") ; continue ; }
+ done
+}
+
+# shellcheck disable=SC2206 # checked by "validate"; ok to expand prerel id's into array
+function compare_version {
+ local order
+ validate_version "$1" V
+ validate_version "$2" V_
+
+ # compare major, minor, patch
+
+ local left=( "${V[0]}" "${V[1]}" "${V[2]}" )
+ local right=( "${V_[0]}" "${V_[1]}" "${V_[2]}" )
+
+ order=$(compare_fields left right)
+ [ "$order" -ne 0 ] && { echo "$order" ; return ; }
+
+ # compare pre-release ids when M.m.p are equal
+
+ local prerel="${V[3]:1}"
+ local prerel_="${V_[3]:1}"
+ local left=( ${prerel//./ } )
+ local right=( ${prerel_//./ } )
+
+ # if left and right have no pre-release part, then left equals right
+ # if only one of left/right has pre-release part, that one is less than simple M.m.p
+
+ [ -z "$prerel" ] && [ -z "$prerel_" ] && { echo 0 ; return ; }
+ [ -z "$prerel" ] && { echo 1 ; return ; }
+ [ -z "$prerel_" ] && { echo -1 ; return ; }
+
+ # otherwise, compare the pre-release id's
+
+ compare_fields left right
+}
+
+# render_prerel -- return a prerel field with a trailing numeric string
+# usage: render_prerel numeric [prefix-string]
+#
+function render_prerel {
+ if [ -z "$2" ]
+ then
+ echo "${1}"
+ else
+ echo "${2}${1}"
+ fi
+}
+
+# extract_prerel -- extract prefix and trailing numeric portions of a pre-release part
+# usage: extract_prerel prerel prerel_parts
+# The prefix and trailing numeric parts are returned in "prerel_parts".
+#
+PREFIX_ALPHANUM='[.0-9A-Za-z-]*[.A-Za-z-]'
+DIGITS='[0-9][0-9]*'
+EXTRACT_REGEX="^(${PREFIX_ALPHANUM})*(${DIGITS})$"
+
+function extract_prerel {
+ local prefix; local numeric;
+
+ if [[ "$1" =~ $EXTRACT_REGEX ]]
+ then # found prefix and trailing numeric parts
+ prefix="${BASH_REMATCH[1]}"
+ numeric="${BASH_REMATCH[2]}"
+ else # no numeric part
+ prefix="${1}"
+ numeric=
+ fi
+
+ eval "$2=(\"$prefix\" \"$numeric\")"
+}
+
+# bump_prerel -- return the new pre-release part based on previous pre-release part
+# and prototype for bump
+# usage: bump_prerel proto previous
+#
+function bump_prerel {
+ local proto; local prev_prefix; local prev_numeric;
+
+ # case one: no trailing dot in prototype => simply replace previous with proto
+ if [[ ! ( "$1" =~ \.$ ) ]]
+ then
+ echo "$1"
+ return
+ fi
+
+ proto="${1%.}" # discard trailing dot marker from prototype
+
+ extract_prerel "${2#-}" prerel_parts # extract parts of previous pre-release
+# shellcheck disable=SC2154
+ prev_prefix="${prerel_parts[0]}"
+ prev_numeric="${prerel_parts[1]}"
+
+ # case two: bump or append numeric to previous pre-release part
+ if [ "$proto" == "+" ] # dummy "+" indicates no prototype argument provided
+ then
+ if [ -n "$prev_numeric" ]
+ then
+ : $(( ++prev_numeric )) # previous pre-release is already numbered, bump it
+ render_prerel "$prev_numeric" "$prev_prefix"
+ else
+ render_prerel 1 "$prev_prefix" # append starting number
+ fi
+ return
+ fi
+
+ # case three: set, bump, or append using prototype prefix
+ if [ "$prev_prefix" != "$proto" ]
+ then
+ render_prerel 1 "$proto" # proto not same pre-release; set and start at '1'
+ elif [ -n "$prev_numeric" ]
+ then
+ : $(( ++prev_numeric )) # pre-release is numbered; bump it
+ render_prerel "$prev_numeric" "$prev_prefix"
+ else
+ render_prerel 1 "$prev_prefix" # start pre-release at number '1'
+ fi
+}
+
+function command_bump {
+ local new; local version; local sub_version; local command;
+
+ command="$(normalize_part "$1")"
+
+ case $# in
+ 2) case "$command" in
+ major|minor|patch|prerel|release) sub_version="+."; version=$2;;
+ *) usage_help;;
+ esac ;;
+ 3) case "$command" in
+ prerel|build) sub_version=$2 version=$3 ;;
+ *) usage_help;;
+ esac ;;
+ *) usage_help;;
+ esac
+
+ validate_version "$version" parts
+ # shellcheck disable=SC2154
+ local major="${parts[0]}"
+ local minor="${parts[1]}"
+ local patch="${parts[2]}"
+ local prere="${parts[3]}"
+ local build="${parts[4]}"
+
+ case "$command" in
+ major) new="$((major + 1)).0.0";;
+ minor) new="${major}.$((minor + 1)).0";;
+ patch) new="${major}.${minor}.$((patch + 1))";;
+ release) new="${major}.${minor}.${patch}";;
+ prerel) new=$(validate_version "${major}.${minor}.${patch}-$(bump_prerel "$sub_version" "$prere")");;
+ build) new=$(validate_version "${major}.${minor}.${patch}${prere}+${sub_version}");;
+ *) usage_help ;;
+ esac
+
+ echo "$new"
+ exit 0
+}
+
+function command_compare {
+ local v; local v_;
+
+ case $# in
+ 2) v=$(validate_version "$1"); v_=$(validate_version "$2") ;;
+ *) usage_help ;;
+ esac
+
+ set +u # need unset array element to evaluate to null
+ compare_version "$v" "$v_"
+ exit 0
+}
+
+function command_diff {
+ validate_version "$1" v1_parts
+ # shellcheck disable=SC2154
+ local v1_major="${v1_parts[0]}"
+ local v1_minor="${v1_parts[1]}"
+ local v1_patch="${v1_parts[2]}"
+ local v1_prere="${v1_parts[3]}"
+ local v1_build="${v1_parts[4]}"
+
+ validate_version "$2" v2_parts
+ # shellcheck disable=SC2154
+ local v2_major="${v2_parts[0]}"
+ local v2_minor="${v2_parts[1]}"
+ local v2_patch="${v2_parts[2]}"
+ local v2_prere="${v2_parts[3]}"
+ local v2_build="${v2_parts[4]}"
+
+ if [ "${v1_major}" != "${v2_major}" ]; then
+ echo "major"
+ elif [ "${v1_minor}" != "${v2_minor}" ]; then
+ echo "minor"
+ elif [ "${v1_patch}" != "${v2_patch}" ]; then
+ echo "patch"
+ elif [ "${v1_prere}" != "${v2_prere}" ]; then
+ echo "prerelease"
+ elif [ "${v1_build}" != "${v2_build}" ]; then
+ echo "build"
+ fi
+}
+
+# shellcheck disable=SC2034
+function command_get {
+ local part version
+
+ if [[ "$#" -ne "2" ]] || [[ -z "$1" ]] || [[ -z "$2" ]]; then
+ usage_help
+ exit 0
+ fi
+
+ part="$1"
+ version="$2"
+
+ validate_version "$version" parts
+ local major="${parts[0]}"
+ local minor="${parts[1]}"
+ local patch="${parts[2]}"
+ local prerel="${parts[3]:1}"
+ local build="${parts[4]:1}"
+ local release="${major}.${minor}.${patch}"
+
+ part="$(normalize_part "$part")"
+
+ case "$part" in
+ major|minor|patch|release|prerel|build) echo "${!part}" ;;
+ *) usage_help ;;
+ esac
+
+ exit 0
+}
+
+function command_validate {
+ if [[ "$#" -ne "1" ]]; then
+ usage_help
+ fi
+
+ if [[ "$1" =~ $SEMVER_REGEX ]]; then
+ echo "valid"
+ else
+ echo "invalid"
+ fi
+
+ exit 0
+}
+
+case $# in
+ 0) echo "Unknown command: $*"; usage_help;;
+esac
+
+case $1 in
+ --help|-h) echo -e "$USAGE"; exit 0;;
+ --version|-v) usage_version ;;
+ bump) shift; command_bump "$@";;
+ get) shift; command_get "$@";;
+ compare) shift; command_compare "$@";;
+ diff) shift; command_diff "$@";;
+ validate) shift; command_validate "$@";;
+ *) echo "Unknown arguments: $*"; usage_help;;
+esac