#!/bin/bash

echo "Hello world"
exit 0

chmod +x /path/to/script.sh
script.sh

# コマンド1 が何らかの理由で失敗した場合にのみ、コマンド 2 を実行する
command1 || command2

# コマンド 1 が成功して 0 の終了ステータスを発行した場合にのみコマンド 2 を実行する
command1 && command2

hello1.sh && echo $?
# -> Hello World
# -> 0

# スクリプト名を表示する
echo "$0" # -> /home/yourName/bin/hello.sh

# パスを表示せずにスクリプトの名前だけを表示する
echo "$(basename $0)" # -> hello.sh

# 変数宣言
name="Mokhtar"
age=35

# 配列
myarr=(one two three four five)
echo ${myarr[1]} # -> two が表示される(bash は 0-indexed)
echo ${myarr[*]} # -> one two three four five
echo ${myarr} # -> one two three four five

# script1.sh
export name="ymgn"
./script2.sh

# script2.sh
echo $name

# バッククォート文字で囲む
cur_dir=`pwd`
echo $cur_dir

# $() で囲む
cur_dir=$(pwd)
echo $cur_dir

bash -v /path/to/script.sh
bash -x /path/to/script.sh

#!/bin/bash
echo -n "Hello $(basename $0)! May I ask your name: "
read
echo "Hello $REPLY"
exit 0

#!/bin/bash
read -p "May I ask your name: " name
echo "Hello $name"
exit 0

#!/bin/bash
read -p "May I ask your name: " name
echo "Hello $name"
read -n1 "Press any key to exit"
echo
exit 0

./script1.sh -a -b -c -- p1 p2 p3

#!/bin/bash
while read line
do
  echo $line
done < yourfile.txt

test EXPRESSION

# ! を使用して評価を反転させる書き方
test ! EXPRESSION

# 複数の式を評価に含める場合は -a (AND) または -o (OR) オプションを付ける
test EXPRESSION1 -a EXPRESSION
test EXPRESSION -o EXPRESSION

[EXPRESSION]

test "$USER" = root

# 角括弧を使う場合
[ "$USER" = root ]

test ! "$USER" = root

# 角括弧を使う場合
[ ! "$USER" = root ]

test "$#" -gt 0
[ "$#" -gt 0 ]

if [ "$#" -lt 1 ] ; then
  echo "Usage: $0 <name>"
  exit 1
fi
echo "Hello $1"
exit 0

case 式 in
  ケース 1)
    文 1
    文 2
  ;;
  ケース2)
    文1
    文2
  ;;
  *)
    文1
  ;;
esac

name=${1-"Anonymous"}

FILE="my file"
rm $FILE # -> rm my file と解釈され、my というファイルと file というファイルを削除するコマンドになってしまう

rm "$FILE" # rm "my file" と解釈され安全

FILE="my file"

# [[ ... ]] の中では && や || が使え、さらに引用符(" ")を省略可能
[[ -f $FILE && -r $FILE ]] && cat "$FILE"

# 正規表現
[[ $FILE =~ \.pl$ ]] && cp "$FILE" scripts/

a=$(( 2 + 3 ))
echo "$a" # -> 5

count=1
(( count++ ))
echo "$count" # -> 2

count=10
(( count-- ))
(( count > 1 )) && echo "Count is greater than 1"

# if 文と組み合わせることもできる
if (( count > 1 )) ; then
  echo "Count is greater than 1"
fi

for u in bob joe ; do
  echo "$u"
done

# file1.txt

Hello, this is a test
This is the second line
And this is the last line

#!/bin/bash
file="file1.txt"
for var in $(cat "$file")
do
  echo "$var"
done

# 実行結果
Helo,
this
is
a
...

#!/bin/bash
file="file1.txt"
IFS=$"\n" # IFS を改行のみにする
for var in $(cat "$file")
do
  echo "$var"
done

#!/bin/bash

for path in /home/*
do
  if [ -d "$path" ] ; then
    echo "$path is a directory"
  elif [ -f "$path" ] ; then
    echo "$path is a file"
  fi
done

for (( v=1; v <= 10; v++ ))
do
  echo "value is $v"
done

for f in * ; do
  [ -d "$f" ] || continue
  chmod 3777 "$f"
done

for f in * ; do
  [ -d "$f" ] && break 
done
echo "We have found a directory: $f"

function-name() {
  <code to execute>
}

# 例
show_system() {
  echo "The uptime is:"
  uptime
  echo
  echo "CPU Detail"
  lscpu
  echo
  echo "User list"
  who
}

myfunc() {
  arr=$@
  echo "The array from inside the function: ${arr[*]}"
}

test_arr\(1 2 3)
echo "The original array is: ${test_arr[*]}"
myfunc ${test_arr[*]}

myfunc() {
  local myvar=10
}

ifconfig eth0 | grep -i "rx packets"