Shulou(Shulou.com)06/01 Report--

This article introduces the relevant knowledge of "the use of rm commands in Linux and the method of code implementation of Candlestick + code". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Preface

Rm command is one of the basic commands in Unix/Linux operating system. The rm command is used to delete files and directories on Linux and other Unix-like operating systems. This command is usually run silently, and you should be very careful when running the rm command, because once you delete a file, you cannot restore the contents of the file and directory.

Linux rm command

Rm deletes each file specified on the command line. By default, it does not delete directories. When rm is executed with the-r or-R option, it recursively deletes any matching directories, their subdirectories, and all files they contain.

The syntax of the rm command:

Rm [option] [- r directory] file name

The items in square brackets are optional. When used only with the names of one or more files, rm deletes all of these files without user confirmation.

The following example will give you a better understanding of how the tool works.

How to use the rm command to delete a file

All you have to do is pass the names of the files (along with the path if they are not in the current working directory) as input to the rm command.

In the following example, rm immediately deletes the names test1.txt, test2.txt

If the file does not exist or the user does not have the appropriate permission to delete it, an error message is returned. Write-protected files prompt the user for confirmation before deletion (y means yes, n means no). Files located even if they are not write-protected, the files in the write-protected directory can never be deleted.

How to force rm to ignore files that do not exist

The-f (mandatory) option tells rm to delete all specified files, whether write-protected or not, without prompting the user. If the specified file does not exist, it does not display an error message or return an error status. However, if you try to delete a file in a write-protected directory, this option will not display an error message.

How to prompt rm before each deletion

The-I (that is, interactive) option tells rm to prompt the user for confirmation before deleting each file and directory. If both the-f and-I options are specified, the last one specified takes effect.

How to use the rm command to delete a directory

As a security measure, rm does not delete directories by default. To delete directories, you need to use the-r option, which is the same as the-R option, which recursively deletes the directory and its contents list in the parameter.

Rm-r [dir name]

That is, the specified directory first clears all subdirectories (including its subdirectories and files, etc.) and files, and then deletes them. The user is usually prompted to delete any write-protected files in the directory unless-use the f option.

Rm-rf [dir name]

How to make rm delete only empty directories

Although you can use the rmdir command to delete directories, you can (and may be easier) to use the rm-d command instead.

How to force rm to issue details of the operation

If you want to delete files and directories, provide detailed output. This can be done using the-v command line option.

The rm command code under Linux implements int main (int argc, char * argv []) {while ((ch = getopt (argc, argv, "dfiRrv"))! =-1) switch (ch) {case'dcards: dflag = 1; break Case'fags: fflag = 1; iflag = 0; break; case'iabilities: fflag = 0; iflag = 1; break Case'Rises: case'rackers: rflag = 1; break; case'vails: vflag = 1; break Case'?': default: usage ();} argc-= optind; argv + = optind; if (argc < 1) {if (fflag) return 0; usage () } signal (SIGINT, progress); checkdot (argv); if (* argv) {stdin_ok = isatty (STDIN_FILENO); if (rflag) rm_tree (argv); else rm_file (argv);} exit (eval);}

Compile and run:

This is the end of the content of "the use of rm commands in Linux and the code implementation of CAccord +". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.