shellfu/include/recon.sh

#!/bin/bash

ffoo import core
ffoo import fun


age_of_leaf() {
    #
    # Print age of each filename on STDIN
    #
    local now=$1
    local ctime
    sed 's/.*/"&"/' \
        | xargs stat -c %Z \
        | while read ctime;
          do echo $(($now - $ctime));
          done
}


age_of_tree() {
    #
    # Age of the youngest leaf in the tree
    #
    local now=$(date +%s)
    find -L "$1" \
        | age_of_leaf $now \
        | sort -n \
        | head -1
}


cat_uri() {
    #
    # Cat for URIs
    #
    wget -q $1 -O - || echo "ERROR: $?" >&2
}


pids_matching() {
    #
    # Print list of PIDs where command matches regex(es)
    #
    # Note that *comm* field of *ps* is used, which may be
    # truncated, so don't rely on name ending
    #
    local all_pids=""
    local pids=""
    local pfx=""
    local pattern
    for pattern in "$@";
    do
        local pids=$(
            ps -e -o pid= -o comm= \
              | perl -ne "
                    chomp;
                    s/^ +//;
                    my (\$pid, \$comm) = split m/ +/;
                    next unless \$comm =~ m/$pattern/;
                    print qq/\$pid /;
                "
        )
        debug -v pattern pids
        all_pids="$all_pids$pfx$pids"
        pfx=" "
    done
    debug -v all_pids
    test -n "$all_pids" && echo $all_pids
}


listening_on() {
    #
    # Check if something is listening on local TCP port $1
    #
    local host="localhost"
    local port="$1"
    debug -v host port
    test -n "$port" || usage_is "PORT"
    netstat -ntlp \
        | sed -e 's/  */ /g' \
        | cut -d\  -f 4 \
        | grep -qs :$port\$
}


reachable_by_ping() {
    #
    # Check if host $1 is reachable by ICMP ping
    #
    local host=$1
    debug -v host
    test -n "$host" || usage_is "HOST"
    ping -w 1 $host >& /dev/null
}


reachable_by_ssh() {
    #
    # Check if host $1 is reachable by SSH
    #
    local host=$1
    debug -v host
    test -n "$host" || usage_is "HOST"
    ssh -n -o ConnectTimeout=3 $host -- true >/dev/null 2>&1;
}


reachable_by_tcp() {
    #
    # Check if TCP port $1 on host $2 is reachable (open)
    #
    local port=$1
    local host=$2
    debug -v port host
    test -n "$host" -a -n "$port" || usage_is "PORT HOST"
    nc -w 1 $host $port >/dev/null 2>&1;
}


filter_hosts() {
    #
    # Filter hosts on STDIN, leaving those reachable
    #
    # Default check is by ICMP only, but you can use arguments
    # to enable/disable checks:
    #
    #   -t|--tcp PORT   enable TCP check on PORT
    #   -p|--ping       enable ICMP ping (default)
    #   -P|--no-ping    disable ICMP ping
    #   -s|--ssh        enable SSH (check by calling `true`)
    #   -S|--no-ssh     disable SSH
    #
    local ping_fun="reachable_by_ping"
    local ssh_fun=true
    local tcp_fun=true
    # note: here the ^ true builtin acts as placeholder (i.e. no check)
    local tcp_port=0
    while true; do case $1 in
        -t|--tcp)       tcp_fun="reachable_by_tcp $2";  shift 2 ;;
        -p|--ping)      ping_fun="reachable_by_ping";   shift   ;;
        -P|--no-ping)   ping_fun=true;                  shift   ;;
        -s|--ssh)       ssh_fun="reachable_by_ssh";     shift   ;;
        -S|--no-ssh)    ssh_fun=true;                   shift   ;;
        "")                                             break   ;;
        *)  usage_is "[-p|P] [-s|-S] [-t port]";        return 2 ;;
    esac done
    filter $ping_fun | filter $tcp_fun | filter $ssh_fun
}


sort_paths_by_age() {
    #
    # Read paths on STDIN and sort them by age of youngest leaf
    #
    while read path;
    do echo "$(age_of_tree $path) $path"
    done \
      | sort -n \
      | cut -d\  -f 2-
}