What is strerror in c++?

C++ strerror() is an inbuilt string handling function that returns the description of the type of system error that occurred in the program. It is defined in header file. It takes an integer parameter, which represents the error code.

What does strerror() do?

The strerror() function returns a pointer to a string that describes the error code passed in the argument errnum, possibly using the LC_MESSAGES part of the current locale to select the appropriate language.

How to use strerror in C?

C Language: strerror function (Convert Error Number to String)

1. Syntax. The syntax for the strerror function in the C Language is: char *strerror(int errnum);
2. Returns. The strerror function returns a pointer to a string that contains an error message for a particular errnum.
3. Required Header.
4. Applies To.
5. Similar Functions.

What library is strerror in?

C library function
C library function – strerror() The C library function char *strerror(int errnum) searches an internal array for the error number errnum and returns a pointer to an error message string. The error strings produced by strerror depend on the developing platform and compiler.

Is strerror thread safe?

strerror is not required to be thread-safe. Implementations may be returning different pointers to static read-only string literals or may be returning the same pointer over and over, pointing at a static buffer in which strerror places the string.

What is perror in Linux?

The perror() function produces a message on standard error describing the last error encountered during a call to a system or library function. To be of most use, the argument string should include the name of the function that incurred the error.

What is Sterror?

Stderr, also known as standard error, is the default file descriptor where a process can write error messages. In Unix-like operating systems, such as Linux, macOS X, and BSD, stderr is defined by the POSIX standard.

Is perror thread safe?

In POSIX systems (like Linux), perror is thread-safe. perror is not listed as non-thread safe here: All functions defined by this volume of POSIX. 1-2008 shall be thread-safe, except that the following functions1 need not be thread-safe.

What does perror return?

The perror() function produces a message on standard error describing the last error encountered during a call to a system or library function. When a system call fails, it usually returns -1 and sets the variable errno to a value describing what went wrong. (These values can be found in

Is stderr a file?

Stderr, also known as standard error, is the default file descriptor where a process can write error messages. In Unix-like operating systems, such as Linux, macOS X, and BSD, stderr is defined by the POSIX standard. Its default file descriptor number is 2. In the terminal, standard error defaults to the user’s screen.

How do I redirect stderr?

To redirect stderr as well, you have a few choices:

1. Redirect stdout to one file and stderr to another file: command > out 2>error.
2. Redirect stdout to a file ( >out ), and then redirect stderr to stdout ( 2>&1 ): command >out 2>&1.

Does errno change perror?

From the man page for errno: Code: Its value is significant only when the call returned an error (usually -1), and a function that does succeed is allowed to change errno. perror() is void, so it can’t return an error (or anything else).

When to use strerror in CString header file?

Header File: string.h (C) or cstring (C++) Explanation: Strerror returns a pointer to a string that contains the identification for an error-number. This is usually used with a function that returns an error number based on the result of an operation. It is a very bad idea to start modifying the string it returns.

What does strerror ( ) do in Linux man?

The strerror () function returns a pointer to a string that describes the error code passed in the argument errnum, possibly using the LC_MESSAGES part of the current locale to select the appropriate language. (For example, if errnum is EINVAL, the returned description will “Invalid argument”.)

Which is the error string produced by strerror?

The error strings produced by strerror depend on the developing platform and compiler. Following is the declaration for strerror () function. errnum − This is the error number, usually errno. This function returns a pointer to the error string describing error errnum. The following example shows the usage of strerror () function.

How to get pointer to error message in strerror?

char * strerror (int errnum); Get pointer to error message string Interprets the value of errnum, generating a string with a message that describes the error condition as if set to errno by a function of the library. The returned pointer points to a statically allocated string, which shall not be modified by the program.