不断检查文件是否被修改bash

我在脚本中有一个名为file1的文件，只要其中有更改，就执行一些操作，实际上会发出蜂鸣声。我怎么做？

如果已经inotify-tools安装（至少是Debian上的软件包名称），则可以执行以下操作：

while inotifywait -q -e modify filename >/dev/null; do
    echo "filename is changed"
    # do whatever else you need to do
done

这等待名为“文件名”的文件发生“修改”事件。发生这种情况时，inotifywait命令输出filename MODIFY（通过将输出发送到/ dev / null将其丢弃），然后终止，这将导致输入循环的主体。

阅读手册页以inotifywait获得更多可能性。

如果没有inotifywait，则可以使用以下小脚本和cron作业（每分钟左右）：

#!/usr/bin/env bash
#
# Provides      : Check if a file is changed
# 
# Limitations   : none
# Options       : none
# Requirements  : bash, md5sum, cut
# 
# Modified      : 11|07|2014
# Author        : ItsMe
# Reply to      : n/a in public
#
# Editor        : joe
#
#####################################
#
# OK - lets work
#

# what file do we want to monitor?
# I did not include commandline options
# but its easy to catch a command line option
# and replace the defaul given here
file=/foo/bar/nattebums/bla.txt

# path to file's saved md5sum
# I did not spend much effort in naming this file
# if you ahve to test multiple files
# so just use a commandline option and use the given
# file name like: filename=$(basename "$file")
fingerprintfile=/tmp/.bla.md5savefile

# does the file exist?
if [ ! -f $file ]
    then
        echo "ERROR: $file does not exist - aborting"
    exit 1
fi

# create the md5sum from the file to check
filemd5=`md5sum $file | cut -d " " -f1`

# check the md5 and
# show an error when we check an empty file
if [ -z $filemd5 ]
    then
        echo "The file is empty - aborting"
        exit 1
    else
        # pass silent
        :
fi

# do we have allready an saved fingerprint of this file?
if [ -f $fingerprintfile ]
    then
        # yup - get the saved md5
        savedmd5=`cat $fingerprintfile`

        # check again if its empty
        if [ -z $savedmd5 ]
            then
                echo "The file is empty - aborting"
                exit 1
        fi

        #compare the saved md5 with the one we have now
        if [ "$savedmd5" = "$filemd5" ]
            then
                # pass silent
                :
            else
                echo "File has been changed"

                # this does an beep on your pc speaker (probably)
                # you get this character when you do:
                # CTRL+V CTRL+G
                # this is a bit creepy so you can use the 'beep' command
                # of your distro
                # or run some command you want to
                echo 
        fi

fi

# save the current md5
# sure you don't have to do this when the file hasn't changed
# but you know I'm lazy and it works...
echo $filemd5 > $fingerprintfile

在MacOS上寻找单线。解决以下。编译并将此工具添加到我的路径中。此过程不到30秒。

$ git clone git@github.com:sschober/kqwait.git
$ cd kqwait
$ make
$ mv kqwait ~/bin
$ chmod +x ~/bin/kqwait

接下来，我转到了要观看的目录。在这种情况下，我希望查看markdown文件中的更改，如果更改，请发出make。

$ while true; do kqwait doc/my_file.md; make; done

而已。

如果您具有diff实用程序，则可能不需要比较md5sum。

if ! diff "$file1" "$file2" >/dev/null 2>&1; then
  echo "$file1 and $file2 does not match" >&2
  ## INSERT-YOUR-COMMAND/SCRIPT-HERE
  ## e.g. cp "$file1" "$file2"
fi

！如果语句为假，则取反，例如为true

需要注意的是，您需要将原始文件与diff进行比较，该差异（imo）与上面的md5sum脚本所做的相同。

您可以尝试使用entr命令行工具，例如

$ ls file1 | entr beep

如果要检查git repo中的更改，则可以使用：

#!/usr/bin/env bash

diff="$(git diff | egrep some_file_name_or_file_path | cat)"

if [[ -n "$diff" ]] ; then
    echo "==== Found changes: ===="
    echo "diff: $diff"
    exit 1
else
    echo 'Code is not changed'
fi

Done in 2 steps Tested and worked fine in both scenarios

一个。cp orginalfile fileneedto_be_changed'（只需要做一次）

orginalfile=====>which supposed to be changed

b。

differencecount=`awk 'NR==FNR{a[$0];next}!($0 in a){print $0}' orginalfile fileneedto_be_changed|wc -l`

if [ $differencecount -eq  0 ]
then
echo "NO changes in file"
else
echo "Noted there is changes in file"
fi