Question

有人可以帮助我使用我的shell脚本吗？我无法弄清楚我做错了什么。我尽可能地把它剥掉了。我错过了这个逻辑。

我的过程相当简单，但显然，我没有正确编码。

这基本上就是我想做的事情：

1. get a list (curr.lst) of directories from remote host
2. perform a `diff` on list of directories with (curr.lst) and a previous list (before.lst)
3. if there is a diff (i'm checking this by doing a `du -b` for file size) = 0 bytes, then nothing 
to report
4. if the diff is greater than 0 bytes, then email me the diff

就是这样。这是我测试它的方式：

1. run the script once
2. edit the before.lst and add/change records to get a diff
3. run again.

我的输出：

$ ./tst.sh
The file size is:0 bytes   **there should be a diff because I just edited the file
No diff found

再次运行：

$ ./tst.sh 
The file size is:83 bytes  **now it found the diff, but when I do an ls my diff.out is 0 bytes, thus I have nothing to mail
Could not exit
Detected a change
Null message body; hope that's ok

我的代码：

#!/usr/local/bin/bash

TEST=/dump/stage/procs
BASE=/home/foobar/dev/mon
KEYFILE=/home/foobar/.ssh/mytestfeed-identity

BEFORE="$BASE/before.lst"
CURR="$BASE/curr.lst"
DIFFOUT="diff.out"
MAIL_RECIP="myname@foobar-inc.com"
SIZE=$(du -b "$BASE/$DIFFOUT" | cut -f 1)
ssh -i $KEYFILE user@host ls "$TEST" | perl -nle 'print $1 if m|$TEST/(\S+)|' > "$CURR" 
diff -b -i $BEFORE $CURR > $BASE/$DIFFOUT 2>&1 
echo "The file size is:$SIZE bytes"       2>&1

if [  "$SIZE" = "0" ]; then
    echo "No diff found" 2>&1
    mv $CURR $BEFORE
    exit
else
    echo "Could not exit" 2>&1
fi

if [  "$SIZE" -gt 0 ]; then
        echo "Detected a change" 2>&1
        mailx -s "Changes detected in $TEST dirs" $MAIL_RECIP < $BASE/$DIFFOUT
        mv $CURR $BEFORE 
fi

Answer 1

在运行du -b "$BASE/$DIFFOUT"之前，您正在执行大小计算（diff）。这意味着您获得在上一次运行脚本期间生成的$DIFFOUT大小。当前运行的$DIFFOUT大小为0，因为您在上一次脚本运行期间将$CURR移至$BEFORE。

我认为您应该只在du行之后移动diff行。

shell编程 - 帮助自动化文件比较并通过电子邮件发送任何更改

1 个答案: