文件表达式
# man test| EXPRESSION | DESCRIPTION | EXAMPLE |
|---|---|---|
| -n STRING | the length of STRING is nonzero | [ -n "$STR" ] |
| -z STRING | the length of STRING is zero | [ -z ${STR} ] |
| -f FILE | FILE exists and is a regular file | [ ! -f ${FILE_1} ] || [ ! -f ${FILE_2} ] |
| -h FILE | FILE exists and is a symbolic link (same as -L) | [ -h "$FILE" ] |
命令
readlink ${FILE} 示例: if [ -h "$LOCAL" ]; then LOCAL=$(readlink ${LOCAL}) fi
readlink -f ${FILE} 示例: MYSELF=$(readlink -f ${0})dirname ${FILE}id -u 示例: [ "$(id -u)" != "0" ]md5sum -c $md5sum_file 示例: md5sum --quiet -c $md5sum_file
