Add scanhost-parallel.sh and documentation for it

README.md

@@ -189,8 +189,23 @@ Run in the following order:
 
    Both tools output pipe separated values.
 
-   Use e.g. `bin/split-up-into-slash24.sh` to split up IP ranges into
-   /24 chunks for parallel scanning.
+### Helper Tools
+
+* Use `bin/split-up-into-slash24.sh` to split up IP ranges into /24
+  chunks for parallel scanning.
+
+  Understands CIDR ranges as commandline options as well as on STDIN.
+
+* `bin/scanhost-parallel.sh` uses above script to scan large IP ranges
+  splitted up into /24 chunks and scanning as many as the CPU provides
+  threads in parallel. Amount can be set via the `-p <n>` option to
+  override number of scans in parallel.
+
+  Understands CIDR ranges as commandline options as well as on STDIN.
+
+  Writes results to `log/<timestamp>/{raw,interpreted}/<ip-range>.log`
+  and interpreted results to STDOUT, too, to provide a progress
+  indicator.
 
 TODO
 ----

bin/scanhost-parallel.sh

@@ -0,0 +1,25 @@
+#?bin/sh
+
+bindir=$(dirname $0);
+datadir="${bindir}/../log/$(date -Iminutes)"
+rawdir="${datadir}/raw"
+intdir="${datadir}/interpreted"
+
+mkdir -pv "${rawdir}" "${intdir}"
+
+if [ "$1" = "-j" ]; then
+    shift
+    p=$1
+    shift;
+else
+    p=$(grep -E '^processor' /proc/cpuinfo | tail -1 | awk '{print $3+1}')
+fi
+
+if [ -n "$*" ]; then
+    echo "$@"
+else
+    cat
+fi | \
+    "${bindir}/split-up-into-slash24.sh" | \
+    xargs -P${p} -I'{}' sh -c \
+          "echo Scanning '{}'; '${bindir}/scanhost.pl' '{}' | tee '${rawdir}'"/'$(echo "{}" | sed -e "s:/[0-9]*\$:.log:") | '"'${bindir}/interpret-versions.pl' | tee '${intdir}'"/'$(echo "{}" | sed -e "s:/[0-9]*\$:.log:")'