Shell-此命令做什么？

Question

Can any body explain to me what this command line do :

find "$dir1" -regex ".*\.exe" -type f -exec cp "{}" "$dir2/my_executable.exe" \;

And I'd like to know why this command has semi-colon at the end.

Thanks a lot!

Answer 1

It looks in $dir for files with .exe extension and copies them to $dir2/my_executable.exe , so that $dir2/my_executable.exe will end up being the last file found.

Explanation

• find "$dir1" looks for files in $dir1 .
• -regex ".*\\.exe" having name XXX.exe .
• -type f being files
• -exec .... {} \\; performs a command in the files found.
• cp "{}" "$dir2/my_executable.exe" \\; copies the found files into "$dir2/my_executable.exe" . As it is always the same, in "$dir2/my_executable.exe" you will end up having the last file found.

Answer 2

This is finding all *.exe files in a directory named $dir1 . Then each of those files are copied with the name of $dir2/my_executable.exe overwriting it every time. So in the end $dir2/my_executable.exe will be same as the last found .exe file in $dir directory.

1. -type f => Find only files
2. -regex ".*\\.exe" => find files with the name with .exe in them
3. -exec => execute a command on each of the found files
4. {} => represents found file name with path
5. cp "{}" "$dir2/my_executable.exe" => copy found file to $dir2/my_executable.exe and the \\; terminates the exec statement

Answer 3

The semicolon at the end is part of the syntax for the -exec option in the find command:

  -exec command ; Execute command; true if 0 status is returned. All following arguments to find are taken to be arguments to the command until an argument consisting of `;' is encountered. The string `{}' is replaced by the current file name being processed everywhere it occurs in the arguments to the command, not just in argu‐ ments where it is alone, as in some versions of find. Both of these constructions might need to be escaped (with a `\\') or quoted to protect them from expansion by the shell. See the EXAMPLES section for examples of the use of the -exec option. The specified command is run once for each matched file. The command is executed in the starting directory. There are unavoidable security problems surrounding use of the -exec action; you should use the -execdir option instead.