Unix命令列實用工具指令碼

#!/bin/bash
# 計算可執行命令數量：簡單的指令碼，用於統計當前PATH中可執行命令的數量
IFS=":"
count=0 ; nonex=0
for directory in $PATH ; do
  if [ -d "$directory" ] ; then
    for command in "$directory"/* ; do
      if [ -x "$command" ] ; then
        count="$(( $count + 1 ))"
      else
        nonex="$(( $nonex + 1 ))"
      fi
    done
  fi
done
echo "$count 個命令，$nonex 個不可執行的條目"
exit 0

#!/bin/bash
# fmt--文字格式化工具，作為nroff的包裝器
# 新增兩個有用的標誌：-w X 用於指定行寬，-h 用於啟用斷字功能以改善填充效果
while getopts "hw:" opt; do
  case $opt in
    h ) hyph=1 ;;
    w ) width="$OPTARG" ;;
  esac
done
shift $(($OPTIND - 1))
nroff << EOF
.ll ${width:-72}
.na
.hy ${hyph:-0}
.pl 1
\ $(cat "$@")
EOF
exit 0

$ fmt -h -w 50 input.txt

#!/bin/bash
# newrm--A replacement for the existing rm command.
# This script provides a rudimentary unremove capability by creating and
# utilizing a new directory within the user's home directory. It can handle
# directories of content as well as individual files. If the user specifies
# the -f flag, files are removed and NOT archived.

archivedir="$HOME/.deleted-files"
realrm="$(which rm)"
copy="$(which cp) -R"

if [ $# -eq 0 ] ; then 
  exec $realrm 
fi

flags=""
while getopts "dfiPRrvW" opt
do
  case $opt in
    f ) exec $realrm "$@" ;; 
    * ) flags="$flags -$opt" ;; 
  esac
done
shift $(( $OPTIND - 1 ))

if [ ! -d $archivedir ] ; then
  if [ ! -w $HOME ] ; then
    echo "$0 failed: can't create $archivedir in $HOME" >&2
    exit 1
  fi
  mkdir $archivedir
  chmod 700 $archivedir 
fi

for arg
do
  newname="$archivedir/$(date "+%S.%M.%H.%d.%m").$(basename "$arg")"
  if [ -f "$arg" -o -d "$arg" ] ; then
    $copy "$arg" "$newname"
  fi
done

exec $realrm $flags "$@" 

alias rm='/path/to/newrm'

$ ls ~/.deleted-files
ls: /Users/taylor/.deleted-files/: No such file or directory
$ newrm file-to-keep-forever
$ ls ~/.deleted-files/
51.36.16.25.03.file-to-keep-forever

#!/bin/bash
# unrm--從已刪除檔案存檔中搜尋指定的檔案或目錄。
# 如果有多個匹配結果，則顯示按時間戳記排序的結果列表，並讓使用者指定要還原的版本。

archivedir="$HOME/.deleted-files"
realrm="$(which rm)"
move="$(which mv)"
dest=$(pwd)

if [ ! -d $archivedir ] ; then
  echo "$0: 沒有已刪除檔案目錄：無內容可還原" >&2
  exit 1
fi

cd $archivedir

# 若未提供引數，則顯示已刪除檔案存檔的內容
if [ $# -eq 0 ] ; then
  echo "您的已刪除檔案存檔內容（按日期排序）："
  ls -FC | sed -e 's/\([[:digit:]][[:digit:]]\.\)\{5\}//g' \
              -e 's/^/ /'
  exit 0
fi

# 否則，必須有使用者指定的模式來進行匹配
matches="$(ls -d *"$1" 2> /dev/null | wc -l)"

if [ $matches -eq 0 ] ; then
  echo "在已刪除檔案存檔中找不到 \"$1\" 的匹配結果。" >&2
  exit 1
fi

if [ $matches -gt 1 ] ; then
  echo "在存檔中找到多個與 \"$1\" 匹配的檔案或目錄："
  index=1
  for name in $(ls -td *"$1")
  do
    datetime="$(echo $name | cut -c1-14 | \
                awk -F. '{ print $5"/"$4" at "$3":"$2":"$1 }')"
    filename="$(echo $name | cut -c16-)"
    
    if [ -d $name ] ; then
      filecount="$(ls $name | wc -l | sed 's/[^[:digit:]]//g')"
      echo " $index) $filename (包含 ${filecount} 個專案，刪除於 $datetime)"
    else
      size="$(ls -sdk1 $name | awk '{print $1}')"
      echo " $index) $filename (大小 = ${size}Kb，刪除於 $datetime)"
    fi
    
    index=$(( $index + 1 ))
  done
  
  echo ""
  /bin/echo -n "應還原哪個版本的 \"$1\"？（輸入 '0' 離開）[1] : "
  read desired
  
  # 使用者輸入驗證與還原邏輯
  if [ ! -z "$(echo $desired | sed 's/[[:digit:]]//g')" ] ; then
    echo "$0: 使用者取消還原：無效輸入。" >&2
    exit 1
  fi
  
  if [ ${desired:=1} -ge $index ] ; then
    echo "$0: 使用者取消還原：索引值太大。" >&2
    exit 1
  fi
  
  if [ $desired -lt 1 ] ; then
    echo "$0: 使用者取消還原。" >&2
    exit 1
  fi
  
  restore="$(ls -td1 *"$1" | sed -n "${desired}p")"
  
  if [ -e "$dest/$1" ] ; then
    echo "\"$1\" 已存在於此目錄中。無法覆寫。" >&2
    exit 1
  fi
  
  /bin/echo -n "正在還原檔案 \"$1\" ..."
  $move "$restore" "$dest/$1"
  echo "完成。"
  
  /bin/echo -n "是否刪除其他版本的 \"$1\"？[y] "
  read answer
  
  if [ ${answer:=y} = "y" ] ; then
    $realrm -rf *"$1"
    echo "已刪除。"
  else
    echo "其他版本保留。"
  fi
else
  # 若只有一個匹配結果，直接還原
  if [ -e "$dest/$1" ] ; then
    echo "\"$1\" 已存在於此目錄中。無法覆寫。" >&2
    exit 1
  fi
  
  restore="$(ls -d *"$1")"
  /bin/echo -n "正在還原檔案 \"$1\" ... "
  $move "$restore" "$dest/$1"
  echo "完成。"
fi

exit 0

#!/bin/bash
# unrm--A simple file undelete utility
archive="/path/to/deleted/files/archive"
if [ $# -eq 0 ] ; then
    echo "Contents of your deleted files archive (sorted by date):"
    ls -lt "$archive"
    exit 0
fi
...

#!/bin/bash
# logrm--Logs all file deletion requests unless the -s flag is used
removelog="/var/log/remove.log"
if [ $# -eq 0 ] ; then
    echo "Usage: $0 [-s] list of files or directories" >&2
    exit 1
fi
if [ "$1" = "-s" ] ; then
    shift
else
    echo "$(date): ${USER}: $@" >> $removelog
fi
/bin/rm "$@"
exit 0