我的Bash腳本有什麼錯誤？ （第43行：在意外標記「elif」附近出現語法錯誤）

Question

我在線上關注了Lynda.com課程。

我正在努力學習所有我能做的事情，但我仍然在命令替換，數組和陣列中掙扎，並且有時會出現If循環。

#!/bin/bash 
MLOG="/var/log/mail.log" 
SLOG="/var/log/syslog" 

echo "Which log(s) do you want to see? " 

echo "[1] Head Of Mail.log?" 
echo "[2] Head Of Syslog?" 
echo "[3] Tail Of Mail.log?" 
echo "[4] Tail Of Syslog?" 
echo "[5] Dump Mail.log to File?" 
echo "[6] Dump Syslog to File?" 


read -p "Select an option [1-6]: " OPTION 

if 
test "$OPTION" -eq "1" 
then 

head $MLOG 

elif 
test "$OPTION" -eq "2" 
then 
head $SLOG 

elif 
test "$OPTION" -eq "3" 
tail $MLOG 

elif 
test "$OPTION" -eq "4" 
tail $SLOG 

elif 
test "$OPTION" -eq "5" 
cat "$MLOG" > ./MessageLogDump.txt 
echo "Message.Log Successfully Dumped in PWD" 

elif 
test "$OPTION" -eq "6" 
cat "$SLOG" > ./SysLog.txt 
echo "Syslog Successfully Dumped in PWD" 

else $? -ne "0" 
echo "Something went wrong somewhere" 

else z $OPTION 
echo "You selected an incorrect option" 
fi 

有錯誤我收到任何輸出：即使只的標準輸入「1」

./GenSysLog.sh: line 43: syntax error near unexpected token `elif' 
./GenSysLog.sh: line 43: `  elif' 

我試圖尋找在這裏的其他問題和答案有同樣的錯誤，我注意到人們提到關於CR & LF，但我仍然無法弄清楚。

謝謝。

Answer 1

請勿使用除環境變量和內置shell變量以外的大寫變量名 - 這樣做會增加命名空間衝突的風險。除此之外，請考慮case聲明：

error() { echo "Something went wrong somewhere"; } 
trap error ERR 

read -p "Select an option [1-6]: " option 
case $option in 
    1) head "$MLOG" ;; 
    2) head "$SLOG" ;; 
    3) tail "$MLOG" ;; 
    4) tail "$SLOG" ;; 
    5) cat "$MLOG" > ./MessageLogDump.txt 
    echo "Message.Log Successfully Dumped in PWD" ;; 
    6) cat "$SLOG" > ./SysLog.txt 
    echo "Syslog Successfully Dumped in PWD";; 
    *) echo "You selected an incorrect option" ;; 
esac 

更短且易於閱讀。