如何在bash-in循环中使用dd命令

我对bash不是很精通，但我知道一些命令，并且可以四处走动。我在编写脚本填充运行Ubuntu（嵌入式Linux）的外部设备上的闪存驱动器时遇到问题

我想知道闪存驱动器何时充满（停止向其中写入随机数据），以便继续执行其他操作

在Python中，我将执行以下操作：

while ...condition:

    if ....condition:
        print "Writing data to NAND flash failed ...."
        break
else:
    continue

---

但我不知道如何在bash中做到这一点。提前感谢您的帮助

根据

手册dd

：

DIAGNOSTICS
     The dd utility exits 0 on success, and >0 if an error occurs.

这就是您在脚本中应该做的，只需在dd命令后检查返回值：

dd if=/dev/urandom of=/storage/testfile.txt
ret=$?
if [ $ret gt 0 ]; then
    echo "Writing data to NAND flash failed ...."
fi

试试这个

#!/bin/bash

filler="$1"     #save the filename
path="$filler"

#find an existing path component
while [ ! -e "$path" ]
do
    path=$(dirname "$path")
done

#stop if the file points to any symlink (e.g. don't fill your main HDD)
if [ -L "$path" ]
then
    echo "Your output file ($path) is an symlink - exiting..."
    exit 1
fi

# use "portable" (df -P)  - to get all informations about the device
read s512 used avail capa mounted <<< $(df -P "$path" | awk '{if(NR==2){ print $2, $3, $4, $5, $6}}')

#fill the all available space
dd if=/dev/urandom of="$filler" bs=512 count=$avail 2>/dev/null
case "$?" in
    0) echo "The storage mounted to $mounted is full now" ;;
    *) echo "dd errror" ;;
esac
ls -l "$filler"
df -P "$mounted"

---

代码是在

的帮助下完成的，上面的

dd

将运行，直到驱动器被填满，并且每次都将退出

>0

。因此，不需要进行任何测试-当脚本在dd之后继续时-驱动器已满..；）@jm666-除非

dd

因其他错误而提前退出。我认为要正确执行此操作，您需要知道闪存驱动器可以容纳多少字节，并明确告诉

dd

写入那么多字节。

#!/bin/bash

filler="$1"     #save the filename
path="$filler"

#find an existing path component
while [ ! -e "$path" ]
do
    path=$(dirname "$path")
done

#stop if the file points to any symlink (e.g. don't fill your main HDD)
if [ -L "$path" ]
then
    echo "Your output file ($path) is an symlink - exiting..."
    exit 1
fi

# use "portable" (df -P)  - to get all informations about the device
read s512 used avail capa mounted <<< $(df -P "$path" | awk '{if(NR==2){ print $2, $3, $4, $5, $6}}')

#fill the all available space
dd if=/dev/urandom of="$filler" bs=512 count=$avail 2>/dev/null
case "$?" in
    0) echo "The storage mounted to $mounted is full now" ;;
    *) echo "dd errror" ;;
esac
ls -l "$filler"
df -P "$mounted"

bash ddd.sh /path/to/the/filler/filename