shell

文件

文件的操作主要是类型（目录，文件，块，套接字）判断，基本操作（创建，删除，遍历，属性修改），读写等；

类型判断

• -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.

例子

#!/bin/bash

if [ ! -f $1 ]; then
    echo "file=$1 not exist"
else
    echo "file=$1 exist"
fi

if [ ! -x $1 ]; then
    echo "file=$1 not exist or the file has not execution permission"
else
    echo "file=$1 and file has execution permission"
fi

创建文件

遍历文件夹

#!/bin/bash

if [ ! -d $1 ]; then
    echo "pleace input a directory"
    exit
fi

# the function can not deal with file with space
function list_files() {
    # param1: directory name to list, don`t state the variable for input parameter, it will work in iterator later,
    # you can use the keyword local to make the variable to work only in current function
    # clear the last /
    local directory=${1%*/}
    for file in `ls $directory`
    do
        path="$directory/$file"
        if [ -f $path ]; then
            echo "file=$path"
        elif [ -d $path ]; then
            echo "directory=$path"
            list_files "$path"
        else
            echo "unkown=$path"
        fi

    done
}

list_files $1

判断

循环