Question

我说,用印本做是新鲜事,但我不敢肯定如何做。我有一个指挥,试图在具体的道路上安装一个磁盘。综合安全分遣队1被定义为在某个特定USB港口进行特别的SSD驱使——这里并不重要。

/bin/mount DISK1 ${MOUNT_PATH}

我现在要检查这一增长是否成功。通常,如果这一表述成功的话,它就会回去,但一旦出现错误,表达就会回去32。

if [$? -eq 0]; then
   echo "Mounted DISK 1 at ${MOUNT_PATH}"
elif [$? -eq 32]; then
   echo "DISK 1 read error"
else
   echo "FAILED TO MOUNT"
fi

When this script ran, and the expression came back as 32, it went to the elif block, but then I got a "command not found" for this. I assume that because "$?" had already been evaluated, so you can t call "$?" again?

So how would you get it to run the mount expression evaluation again and do a 32 -eq 32 comparison so that it can run the "DISK 1 read error"?

储存评价是解决这一问题的方法吗? 该法典是否可行? 由于磁盘重读错误需要几天才能显示,我很难测试该代码。

/bin/mount DISK1 ${MOUNT_PATH}
$mnt_stat = $?
if [$mnt_stat -eq 0]; then
  echo "Mounted DISK 1 at ${MOUNT_PATH}"
elif [$mnt_stat -eq 32]; then
  echo "DISK 1 read error"
else
  echo "FAILED TO MOUNT"
fi

Answer 1

如果你在上操作你的文字,请见[$mnt_stat -eq 0]。

Also, no space allowed around = variable assignation.

a. 使用现代篮子的适当方式:

mount DISK1 "$MOUNT_PATH"
mnt_stat=$?
if ((mnt_stat==0)); then
    echo "Mounted DISK 1 at $MOUNT_PATH"
elif ((mnt_stat == 32)); then
    echo "DISK 1 read error" >&2
else
    echo "FAILED TO MOUNT" >&2
fi

<代码>(......)和$(......)>>为平价指示,如该表述为非零,则其退约状态为0,或表示为零。如果需要副作用(派任),也可作为“小数”的同义词。

见。

<代码>[或test>>为POSIX测试指令。它可以对档案和地块进行简单的测试。在<条码>bash中,为了一致性,你应使用更强大的<条码>[,而禁止<条码>。 <代码>[>[] 能够做到配对模式、快捷和安全使用。在这种情况下,我们使用<代码>()进行更可读的算术。

See
http://mywiki.wooledge.org/BashGuide/TestsAndConditionals
http://mywiki.wooledge.org/BashFAQ/031

Don t be confused by spaces. they are mandatory with the form

[ ]
[[ ]]

因为它有:commands。

页: 1

(( ))

它只是评价,因此没有空间规则。

Answer 2

除了一些辛塔克斯错误(在<代码>上没有位置[和][和>上下)和错误的派任之外,你还处于正确的轨道上:

Would storing the evaluation be the way to approach this?

是的,由于<代码>[>(aka test)的每项执行都制定了$?,因此,在第一个>>>>>后,你失去<代码>>>/代码>的指挥结果。发言<代码>[。

1. 贵国法典的最低限度修改文本是:

/bin/mount DISK1 "${MOUNT_PATH}"
# (exit 32)  # Uncomment to fake a return value.
mnt_stat=$?  # Save return code (no $ sigil before mnt_stat or spaces around the = here).
if [ $mnt_stat -eq 0 ]; then  # Add spaces around [ and ], but ; doesn t need a space.
  echo "Mounted DISK 1 at ${MOUNT_PATH}"
elif [ $mnt_stat -eq 32 ]; then
  echo "DISK 1 read error"
else
  echo "FAILED TO MOUNT"
fi

友情链接