① linux 目錄是否存在命令
#shell判斷文件夾是否存在
#如果文件夾不存在，創建文件夾
if [ ! -d "/myfolder" ]; then
mkdir /myfolder
fi
#shell判斷文件,目錄是否存在或者具有許可權
folder="/var/www/"
file="/var/www/log"
# -x 參數判斷 $folder 是否存在並且是否具有可執行許可權
if [ ! -x "$folder"]; then
mkdir "$folder"
fi
# -d 參數判斷 $folder 是否存在 《Linux就該這么學》 一起學習linux
if [ ! -d "$folder"]; then
mkdir "$folder"
fi
# -f 參數判斷 $file 是否存在
if [ ! -f "$file" ]; then
touch "$file"
fi
# -n 判斷一個變數是否有值
if [ ! -n "$var" ]; then
echo "$var is empty"
exit 0
fi
# 判斷兩個變數是否相等
if [ "$var1" = "$var2" ]; then
echo '$var1 eq $var2'
else
echo '$var1 not eq $var2'
fi
② 關於linux，shell腳本中怎樣判斷文件是否有內容
可以用「test 條件表達式」進行測試，如：test -f /etc/fstab 測試文件/etc/fstab文件是否存在
-e File 如果文件File存在(Exist),則為True
-s File 如果文件File存在且文件大小(Size)大於零，則為True
-f File 如果文件File存在且是普通文件(File)，則為True
-d File 如果文件File存在且是目錄(Directory)，則為True
-b File 如果文件File存在且是塊(Block)特殊文件，則為True
-c File 如果文件File存在且是字元(Character)特殊文件，則為True
-L File 如果文件File存在且是符號鏈接(Link)文件，則為True
-r File 如果文件File存在且是可讀的(Readable)，則為True
-w File 如果文件File存在且是可寫的(Writable)，則為True
-x File 如果文件File存在且是可執行的(Executable)，則為True
-O File 如果文件File存在且屬於當前用戶(Owner)，則為True
-G File 如果文件File存在且屬於當前用戶組(Group)，則為True
File1 -nt File2 如果文件File1新於(Newer Then) File2，則為True
File2 -ot File2 如果文件File1舊於(Older Then) File2，則為True
③ linux 判斷文件夾是否有某個目錄
1. shell判斷文件,目錄是否存在或者具有許可權
2. #!/bin/sh
3.
4. myPath="/var/log/httpd/"
5. myFile="/var /log/httpd/access.log"
6.
7. # 這里的-x 參數判斷$myPath是否存在並且是否具有可執行許可權
8. if [ ! -x "$myPath"]; then
9. mkdir "$myPath"
10. fi
11.
12. # 這里的-d 參數判斷$myPath是否存在
13. if [ ! -d "$myPath"]; then
14. mkdir "$myPath"
15. fi
16.
17. # 這里的-f參數判斷$myFile是否存在
18. if [ ! -f "$myFile" ]; then
19. touch "$myFile"
20. fi
21.
22. # 其他參數還有-n,-n是判斷一個變數是否是否有值
23. if [ ! -n "$myVar" ]; then
24. echo "$myVar is empty"
25. exit 0
26. fi
27.
28. # 兩個變數判斷是否相等
29. if [ "$var1" = "$var2" ]; then
30. echo '$var1 eq $var2'
31. else
32. echo '$var1 not eq $var2'
33. fi
-f 和-e的區別
Conditional Logic on Files
-a file exists.
-b file exists and is a block special file.
-c file exists and is a character special file.
-d file exists and is a directory.
-e file exists (just the same as -a).
-f file exists and is a regular file.
-g file exists and has its setgid(2) bit set.
-G file exists and has the same group ID as this process.
-k file exists and has its sticky bit set.
-L file exists and is a symbolic link.
-n string length is not zero.
-o Named option is set on.
-O file exists and is owned by the user ID of this process.
-p file exists and is a first in, first out (FIFO) special file or
named pipe.
-r file exists and is readable by the current process.
-s file exists and has a size greater than zero.
-S file exists and is a socket.
-t file descriptor number fildes is open and associated with a
terminal device.
-u file exists and has its setuid(2) bit set.
-w file exists and is writable by the current process.
-x file exists and is executable by the current process.
-z string length is zero.
是用 -s 還是用 -f 這個區別是很大的！
