在默认包管理器v2之外查找侦听网络的过程

Question

这是在默认包管理器之外的网络上查找侦听过程的后续问题

由于使用了/proc，我设法使它变得更快一些，并希望能够实现大多数建议。一些小问题

• 我们能摆脱这些管道来支持这里的琴弦吗？我试过，但遇到了问题。
• 我们能摆脱自定义的readarray函数吗？它占用了太多的空间，只使用过一次。一直在努力寻找一个简洁的替代品。
• 与以前一样，代码需要支持bash 3.2+，因此遗憾的是，没有许多出色的特性可用。

和以前一样，它的工作原理与预期一样。

Improved代码

#!/bin/bash

# finds processes listening in on the network outside outside of the default package manager

usage=$(cat <<-EOF
$(basename "$0").sh [-h] [-f] [-a] [-w] [-v] [-p]

Lists packages listening on the network outside of the default package manager

where:
    -h,  --help                     show this help text
    -f,  --whitelist-file           pick a file[s] containing whitelisted programs
    -w,  --whitelist                explicitly add whitelisted programs
    -W,  --ignore-whitelist         ignore the whitelist, includes env variables
    -v,  --view-whitelist           view the complete whitelist
    -p,  --package-manager          which package-manager to use (rpm, dkpg, ...)
    -P,  --ignore-package-manager   ignores the check for a working package manager

output:
  COMMAND    PATH                PID    USER     FD   TYPE  DEVICE    SIZE/OFF  NODE  NAME
  mattermos  /app/main/mattermo  3351   361000   25u  IPv4  84625698  0t0       TCP   129.240...(ESTABLISHED)

examples:
    List all processes listening on the network
      usit_network_network_listening_processes --list-all 

    List only packages not maintained by the central package manager system
      usit_network_network_listening_processes --list-all 

    Whitelist some processes 
      usit_network_network_listening_processes --whitelist mattermos,systemd
      usit_network_network_listening_processes --whitelist 'mattermos systemd'

    Whitelist some processes using whitelist files
      usit_network_network_listening_processes -f /etc/uio/uio_network_listening_processes_whitelist_01.txt

    Multiple whitelist files is supported
      usit_network_network_listening_processes --whitelist foo.txt,bar.txt

environment variables:
  The following environment variables are available
  
    USIT_LISTENER_WHITELIST
    USIT_LISTENER_WHITELIST_FILES
  
  These form the base for the whitelist and whitelist files respectively. 
  Use a string with spaces or comma [,] as seperator for the values.
EOF
)

fatal() {
    printf "ERROR: $*" >&2
    exit 1
}

# This is a substitute for readarray for older bash versions
# https://stackoverflow.com/a/64793921/1048781
if ! type -t readarray >/dev/null; then
  # Very minimal readarray implementation using read. Does NOT work with lines that contain double-quotes due to eval()
  readarray() {
    local cmd opt t v=MAPFILE
    while [ -n "$1" ]; do
      case "$1" in
      -h|--help) echo "minimal substitute readarray for older bash"; exit; ;;
      -r) shift; opt="$opt -r"; ;;
      -t) shift; t=1; ;;
      -u) 
          shift; 
          if [ -n "$1" ]; then
            opt="$opt -u $1"; 
            shift
          fi
          ;;
      *)
          if [[ "$1" =~ ^[A-Za-z_]+$ ]]; then
            v="$1"
            shift
          else
            echo -en "${C_BOLD}${C_RED}Error: ${C_RESET}Unknown option: '$1'\n" 1>&2
            exit
          fi
          ;;
      esac
    done
    cmd="read $opt"
    eval "$v=()"
    while IFS= eval "$cmd line"; do      
      line=$(echo "$line" | sed -e "s#\([\"\`]\)#\\\\\1#g" )
      eval "${v}+=(\"$line\")"
    done
  }
fi

# Transform long options to short ones
args=()

for arg; do
    case $arg in
    '--whitelist')                args+=(-w) ;;
    '--whitelist-file')           args+=(-f) ;;
    '--ignore-whitelist')         args+=(-W) ;;
    '--ignore-package-manager')   args+=(-P) ;;
    '--view-whitelist')           args+=(-v) ;;
    '--package-manager')          args+=(-p) ;;
    '--help')                     args+=(-h) ;;
    *)                            args+=("$arg") ;;
    esac
done

set -- "${args[@]}"

# The '//,/ ' allows us to input variables using , seperator as well as SPACE
whitelist=()
whitelist_files=()
read -ar whitelist <<< "${USIT_LISTENER_WHITELIST//,/ }"
read -ar whitelist_files <<< "${USIT_LISTENER_WHITELIST_FILES//,/ }"
view_whitelist=false
ignore_whitelist=false
ignore_package_manager=false
while getopts ":w:f:p:vPWh" flag; do
    case "${flag}" in
    h)
        echo "$usage"
        exit 0
        ;;
    v) view_whitelist=true ;;
    W) ignore_whitelist=true ;;
    P) ignore_package_manager=true ;;
    w) read -ra parts <<< "${OPTARG//,/ }"
       whitelist+=("${parts[@]}")
       ;;
    f) read -ra parts <<< "${OPTARG//,/ }"
       whitelist_files+=("${parts[@]}")
       ;;
    p) package_manager=${OPTARG} ;;
    \?)
        fatal "illegal option: -%s${OPTARG} \n\n$usage\n\n"
        ;;
    esac
done

# -i : This option filters only processes whith an IPv[46] address:
# -P : This option inhibits the conversion of port numbers to port names for network files.
# -n : This option inhibits the conversion of network numbers to host names for network files.
# -l : This option inhibits the conversion of user ID numbers to login names.
# +M : Enables the reporting of portmapper registrations for local TCP and UDP ports.
# The awk filters only unique PID's by  _[val] looks up val in the hash _(a regular variable).
# NR > 1 is used to skip the header
network_listening_processes=$(
  lsof -Pnl +M -i | 
    awk 'NR>1 && !seen[$1]++ { print }' 
)
# we use the realpath -m to extract the execution path from the process id (pid)
network_listening_processes_with_path=$(
    while read -r a pid b; do
        printf "%s %s %s %s\n" "$a" "'$(realpath -m /proc/"$pid"/exe)'" "$pid" "$b"
    done <<< "${network_listening_processes[@]}"
)
if "${ignore_whitelist}" && "${ignore_package_manager}"; then
    echo "${network_listening_processes_with_path}" | column -t
    exit
fi

function is_in_array {
    local array="$1[@]"
    local seeking="${!2}"
    local result=1
    for element in "${!array}"; do
        if [[ $element == "$seeking" ]]; then
            result=0
            break
        fi
    done
    return $result
}

function is_empty_array {
    local array="$1[@]"
    for element in "${!array}"; do
        return 1
    done
    return 0
}

function print_array {
    local array="$1[@]"
    for element in "${!array}"; do
        echo "${element}"
    done
}

# Block of code for getting the correct package manager
is_in_standard_repo_rpm() {
    rpm -qf "${1}" &>/dev/null
}
is_in_standard_repo_dpkg() {
    dpkg -S "${1}" &>/dev/null
}
is_in_standard_repo_any() {
    local package="${1}"
    return 1
}
if "${ignore_package_manager}"; then
    package_manager="any"
else
    dpkg_equivalents=("dpkg" "apt" "")
    rpm_equivalents=("rpm" "yum" "dnf" "")
    if is_in_array dpkg_equivalents package_manager && dpkg --version &>/dev/null; then
        package_manager="dpkg"
    elif is_in_array rpm_equivalents package_manager && rpm --version &>/dev/null; then
        package_manager="rpm"
    else
        fatal "No supported package manager found! Try specifying one with -p --package-manager"
    fi
fi
is_in_standard_repo () {
    is_in_standard_repo_$package_manager "${!1}"
}

# block of code for handling the whitelist
if "${ignore_whitelist}"; then
    whitelist=()
else
    if ! is_empty_array whitelist_files; then
        readarray -t whitelist_from_file < <(sort -u "${whitelist_files[@]}")
        whitelist+=("${whitelist_from_file[@]}")
    fi
fi
if "${view_whitelist}"; then
    ! is_empty_array whitelist && print_array whitelist
    exit
fi

# Finally we list every process not in the default packagen_manager
# Which is listening on the network
while IFS= read -r line; do
    programname=$(awk '{print $1}' <<< "${line}")
    path=$(awk '{print $2}' <<< "${line}")
    path_without_quotes=$(sed 's/^.\(.*\).$/\1/' <<< "${path}")
    if ! is_in_standard_repo path_without_quotes && ! is_in_array whitelist programname; then
        echo "${line}"
    fi
done <<< "${network_listening_processes_with_path}" | column -t

Answer 1