實現代碼一、
#!/bin/sh
# 判斷文件是否存在
# link：www.jb51.net
# date：2013/2/28
myPath="/var/log/httpd/"
myFile="/var /log/httpd/access.log"
# 這里的-x 參數判斷$myPath是否存在并且是否具有可執(zhí)行權限
if [ ! -x "$myPath"]; then
mkdir "$myPath"
fi
# 這里的-d 參數判斷$myPath是否存在
if [ ! -d "$myPath"]; then
mkdir "$myPath"
fi
# 這里的-f參數判斷$myFile是否存在
if [ ! -f "$myFile" ]; then
touch "$myFile"
fi
# 其他參數還有-n,-n是判斷一個變量是否是否有值
if [ ! -n "$myVar" ]; then
echo "$myVar is empty"
exit 0
fi
# 兩個變量判斷是否相等
if [ "$var1" = "$var2" ]; then
echo '$var1 eq $var2'
else
echo '$var1 not eq $var2'
fi
實現代碼二、
#shell判斷文件夾是否存在
#如果文件夾不存在，創(chuàng)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權限
folder="/var/www/"
file="/var/www/log"
# -x 參數判斷 $folder 是否存在并且是否具有可執(zhí)行權限
if [ ! -x "$folder"]; then
mkdir "$folder"
fi
# -d 參數判斷 $folder 是否存在
if [ ! -d "$folder"]; then
mkdir "$folder"
fi
# -f 參數判斷 $file 是否存在
if [ ! -f "$file" ]; then
touch "$file"
fi
# -n 判斷一個變量是否有值
if [ ! -n "$var" ]; then
echo "$var is empty"
exit 0
fi
# 判斷兩個變量是否相等
if [ "$var1" = "$var2" ]; then
echo '$var1 eq $var2'
else
echo '$var1 not eq $var2'
fi
-f 和-e的區(qū)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(qū)別是很大的！
您可能感興趣的文章:- Shell腳本創(chuàng)建指定大小文件的測試數據
- shell按行讀取文件的3種方法
- Shell中建立與使用臨時性文件的方法詳解
