文章内容
一、参数说明
1 2 3 4 5 6 7 8 9 | -e filename 如果 filename存在，则为真 -d filename 如果 filename为目录，则为真 -f filename 如果 filename为常规文件，则为真 -L filename 如果 filename为符号链接，则为真 -r filename 如果 filename可读，则为真 -w filename 如果 filename可写，则为真 -x filename 如果 filename可执行，则为真 -s filename 如果文件长度不为0，则为真 -h filename 如果文件是软链接，则为真 |
其他：
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 | -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. |
二、常用判断示例
1、判断文件夹是否存在
1 2 3 4 5 | #shell判断文件夹是否存在#如果文件夹不存在，创建文件夹if [ ! -d "/myfolder" ]; then mkdir /myfolderfi |
2、判断文件夹是否存在并且是否具有可执行权限
1 2 3 4 5 6 7 8 | #shell判断文件,目录是否存在或者具有权限folder="/var/www/"file="/var/www/log"# -x 参数判断 $folder 是否存在并且是否具有可执行权限if [ ! -x "$folder"]; then mkdir "$folder"fi |
3、判断文件夹是否存在
1 2 3 4 | # -d 参数判断 $folder 是否存在if [ ! -d "$folder"]; then mkdir "$folder"fi |
4、判断文件是否存在
1 2 3 4 | # -f 参数判断 $file 是否存在if [ ! -f "$file" ]; then touch "$file"fi |
5、判断一个变量是否有值
1 2 3 4 5 | # -n 判断一个变量是否有值if [ ! -n "$var" ]; then echo "$var is empty" exit 0fi |
6、判断两个变量是否相等
1 2 3 4 5 6 | # 判断两个变量是否相等if [ "$var1" = "$var2" ]; then echo '$var1 eq $var2'else echo '$var1 not eq $var2'fi |