技術標籤：Linuxlinux

練習題一

使用date命令來顯示當前的日期和時間

[[email protected] ~]$ date
Wed Dec 23 11:02:47 CST 2020

練習題二

2.以12小時制顯示當前時間（例如，11:42:11AM）。提示：顯示該輸出的格式字串為%r

[[email protected] ~]$ date  +%r
11:08:03 AM

練習題三

3/home/student/zcat的檔案型別是什麼？可否被人讀取？

[[email protected] ~]$ ll /home/student/
total 4
-rwxr-xr-x. 1 student student 1983 Dec 23 11:11 zcat
 

檔案型別：普通檔案
可否被人讀取：可以被人讀取

通 過 命 令 查 詢 文 件 類 型 \color{#FF3030}{通過命令查詢檔案型別} 通過命令查詢文件類型

[[email protected] ~]$ file zcat
zcat: POSIX shell script, ASCII text executable

練習題四

使用wc命令和bash快捷鍵顯示zcat的大小

使用wc命令顯示zcat的大小

[[email protected] ~]$ wc -c /home/student/zcat
1983 /home/student/zcat

正 確 的 操 作 ： w c + E S C + . \color{#FF3030}{正確的操作：wc+ESC+.}

練習題五

顯示zcat的前10行

[[email protected] ~]$ head -10 /home/student/zcat
#!/bin/sh
# Uncompress files to standard output.

# Copyright (C) 2007, 2010-2018 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
 

# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.

練習題六

顯示zcat檔案後10行

[[email protected] ~]$ tail -10 /home/student/zcat
With no FILE, or when FILE is -, read standard input.

Report bugs to <[email protected]>."

case $1 in
--help)    printf '%s\n' "$usage"   || exit 1; exit;;
--version) printf '%s\n' "$version" || exit 1; exit;;
esac

exec gzip -cd "[email protected]"

練習題七

重複上一命令，但使用-n 20 選項來顯示檔案中最後20行。使用命令編輯功能，以通過最少擊鍵次數來完成此操縱

[[email protected] ~]$ tail -20 /home/student/zcat
  -l, --list        list compressed file contents
  -q, --quiet       suppress all warnings
  -r, --recursive   operate recursively on directories
  -S, --suffix=SUF  use suffix SUF on compressed files
      --synchronous synchronous output (safer if system crashes, but slower)
  -t, --test        test compressed file integrity
  -v, --verbose     verbose mode
      --help        display this help and exit
      --version     display version information and exit

With no FILE, or when FILE is -, read standard input.

Report bugs to <[email protected]>."

case $1 in
--help)    printf '%s\n' "$usage"   || exit 1; exit;;
--version) printf '%s\n' "$version" || exit 1; exit;;
esac

exec gzip -cd "[email protected]"

練習題八

使用shell歷史記錄來再次執行date +%r命令

[[email protected] ~]$ history
[[email protected] ~]$ !11
date  +%r
11:24:32 AM