commit: 33eb256fea09d4113b6b9dffa2752b6abf997324
parent: 62d5518179e42ea5970401b41efcbb8fc33e6bd0
author: z0noxz <chris@noxz.tech>
date: Tue, 7 Aug 2018 08:28:39 +0200
make POSIX compliant
1 file changed, 54 insertions(+), 47 deletions(-)
diff --git a/ip2cidr b/ip2cidr
@@ -1,6 +1,6 @@
#!/bin/sh
-read -d '' license << EOF
-Converts IPADDRESS to CIDR, or return CIDR if already a valid one
+license='
+Converts IPADDRESS to CIDR, or returns CIDR if already a valid one
Copyright (C) 2018 z0noxz, <chris@noxz.tech>
This program is free software: you can redistribute it and/or modify
@@ -15,66 +15,73 @@ 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/>.
-EOF
+'
-function ip2cidr {
+count_ones() {
- local ip=$1
- local OIFS=$IFS
- local D2B=({0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1})
- local binary=""
- local ones=""
+ dec=$1
+ base=2
+ result=0
- IFS=\. read -ra ip <<< "$ip"
- IFS=$OIFS
-
- binary="${D2B[ip[0]]}${D2B[ip[1]]}${D2B[ip[2]]}${D2B[ip[3]]}"
- ones="${binary//0}"
+ while [ "$dec" -ne 0 ]; do
+ if [ $((dec % base)) -eq 1 ]; then
+ result=$((result+1))
+ fi
+ dec=$((dec / base))
+ done
- printf "%d\n" ${#ones}
+ printf '%d' "$result"
}
-function isip {
-
- local ip=$1
- local OIFS=$IFS
-
- if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
- IFS=\. read -ra ip <<< "$ip"
- IFS=$OIFS
- if [[ \
- ${ip[0]} -le 255 &&\
- ${ip[1]} -le 255 &&\
- ${ip[2]} -le 255 &&\
- ${ip[3]} -le 255 \
- ]]; then
- return 0
+do_ip2cidr() {
+
+ ip=$1
+ OIFS=$IFS
+ result=0
+ i=0
+
+ IFS=\.
+ for item in $ip; do
+ if [ "$item" -eq "$item" ] 2> /dev/null && \
+ [ "$item" -le 256 ] && [ "$item" -ge 0 ]; then
+ i=$((i+1))
+ case $i in
+ 1)
+ result=$((result+item*16777216))
+ ;;
+ 2)
+ result=$((result+item*65536))
+ ;;
+ 3)
+ result=$((result+item*256))
+ ;;
+ 4)
+ result=$((result+item))
+ ;;
+ esac
+ else
+ return 1
fi
- fi
- return 1
+ done
+ IFS=$OIFS
+
+ printf '%d\n' "$(count_ones "$result")"
}
-# check if input already is a CIDR
-if [[ $1 =~ ^[0-9]{1,2}$ && $1 -le 32 && $1 -gt 0 ]]; then
- echo "$1"
- exit 0
+# check if input already is a CIDR, and if not process it
+if [ "$1" -eq "$1" ] 2> /dev/null && [ "$1" -le 32 ] && [ "$1" -gt 0 ]; then
+ printf '%d\n' "$1" && exit 0
+else
+ do_ip2cidr "$1" && exit 0
fi
-# check if input is a valid IP, then return CIDR from IP
-if isip $1; then
- ip2cidr $1
- exit 0
-fi
# if all fails print usage
program_name="${0##*/}"
-read -d '' usage << EOF
-Usage: $program_name IPADDRESS
+printf 'Usage: %s IPADDRESS
LICENSE NOTICE
-
-$license
-EOF
-printf "%s\n\n" "$usage" >&2
+%s
+' "$program_name" "$license" >&2
exit 1
