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There is an access function in linux; this function is used to check the user's permissions on a file. If the specified access method is valid, the function returns 0; otherwise, the function returns "- 1" with the syntax "int access (const char* pathname, int mode);".

The operating environment of this tutorial: linux7.3 system, Dell G3 computer.

Is there an access function in linux?

There is an access function in linux

Access function header file: unistd.h function: determine the access rights of files or folders. That is, check how a file is accessed, such as read-only, write-only, and so on. If the specified access method is valid, the function returns 0, otherwise the function returns-1.

The syntax is:

# includeint access (const char* pathname, int mode)

Parameter description:

Pathname is the pathname of the file + file name

Mode: specify the role of access. Values are as follows

The F_OK value is 0 to determine whether the file exists.

The X_OK value is 1, which determines that the file is executable.

The W_OK value is 2 to determine whether you have write permission to the file.

The R_OK value is 4 to determine whether you have read permission to the file.

Note: the last three methods can be used together or "|", such as W_OK | R_OK

For example:

Access ("test", 06); access ("test", F_OK)

It is used to check whether the actual user has read and write permissions to the test file and whether the test file exists.

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