使用预设系统信息替换uname

#!/bin/bash

# 系统信息预设
KERNEL_NAME="Linux"
NODENAME="$(hostname 2>/dev/null || echo 'localhost.localdomain')"
KERNEL_RELEASE="3.10.0-957.el7.x86_64"
KERNEL_VERSION="#1 SMP Thu Nov 8 23:39:32 UTC 2018"
MACHINE="x86_64"
PROCESSOR="x86_64"
HARDWARE_PLATFORM="x86_64"
OPERATING_SYSTEM="GNU/Linux"

# 辅助函数前置定义
show_help() {
  cat <<EOF
Usage: uname [OPTION]...
Print certain system information.  With no OPTION, same as -s.

  -a, --all                print all information, in the following order,
                             except omit -p and -i if unknown:
  -s, --kernel-name        print the kernel name
  -n, --nodename           print the network node hostname
  -r, --kernel-release     print the kernel release
  -v, --kernel-version     print the kernel version
  -m, --machine            print the machine hardware name
  -p, --processor          print the processor type or "unknown"
  -i, --hardware-platform  print the hardware platform or "unknown"
  -o, --operating-system   print the operating system
      --help     display this help and exit
      --version  output version information and exit

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'uname invocation'
EOF
}

show_version() {
  cat <<EOF
uname (GNU coreutils) 8.22
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David MacKenzie.
EOF
}

# 选项标志声明
declare -A flags=(
  [s]=0 [n]=0 [r]=0 [v]=0
  [m]=0 [p]=0 [i]=0 [o]=0
)
show_all=false

# 标准化参数解析
while getopts ":asnrvmpio-:" opt; do
  case $opt in
    a) show_all=true ;;
    s) flags[s]=1 ;;
    n) flags[n]=1 ;;
    r) flags[r]=1 ;;
    v) flags[v]=1 ;;
    m) flags[m]=1 ;;
    p) flags[p]=1 ;;
    i) flags[i]=1 ;;
    o) flags[o]=1 ;;
    -) # 长选项处理
      case "${OPTARG}" in
        help) show_help; exit 0 ;;
        version) show_version; exit 0 ;;
        all) show_all=true ;;
        kernel-name) flags[s]=1 ;;
        nodename) flags[n]=1 ;;
        kernel-release) flags[r]=1 ;;
        kernel-version) flags[v]=1 ;;
        machine) flags[m]=1 ;;
        processor) flags[p]=1 ;;
        hardware-platform) flags[i]=1 ;;
        operating-system) flags[o]=1 ;;
        *) echo -e "uname: unrecognized option '--${OPTARG}'\nTry 'uname --help' for more information." >&2; exit 1 ;;
      esac
      ;;
    \?)
      echo -e "uname: invalid option -- '${OPTARG}'\nTry 'uname --help' for more information." >&2
      exit 1
      ;;
  esac
done

# 处理显示逻辑
output=()
if $show_all; then
  # -a 的固定显示顺序
  output=(
    "$KERNEL_NAME"
    "$NODENAME"
    "$KERNEL_RELEASE"
    "$KERNEL_VERSION"
    "$MACHINE"
  )
  [[ "$PROCESSOR" != "unknown" ]] && output+=("$PROCESSOR")
  [[ "$HARDWARE_PLATFORM" != "unknown" ]] && output+=("$HARDWARE_PLATFORM")
  output+=("$OPERATING_SYSTEM")
else
  # 常规选项按固定顺序处理
  [[ ${flags[s]} -eq 1 ]] && output+=("$KERNEL_NAME")
  [[ ${flags[n]} -eq 1 ]] && output+=("$NODENAME")
  [[ ${flags[r]} -eq 1 ]] && output+=("$KERNEL_RELEASE")
  [[ ${flags[v]} -eq 1 ]] && output+=("$KERNEL_VERSION")
  [[ ${flags[m]} -eq 1 ]] && output+=("$MACHINE")
  [[ ${flags[p]} -eq 1 && "$PROCESSOR" != "unknown" ]] && output+=("$PROCESSOR")
  [[ ${flags[i]} -eq 1 && "$HARDWARE_PLATFORM" != "unknown" ]] && output+=("$HARDWARE_PLATFORM")
  [[ ${flags[o]} -eq 1 ]] && output+=("$OPERATING_SYSTEM")
fi

# 默认显示内核名称
[[ ${#output[@]} -eq 0 ]] && output=("$KERNEL_NAME")

# 格式化输出
echo "${output[*]}"

exit 0