C Programming Code Examples
C > File Operations Code Examples
Open a temporary file: how to use tmpfile
/* Open a temporary file: how to use tmpfile */
#include <stdio.h>
int main ()
{
FILE *file;
file = tmpfile();
// file is pointing to a temp file.
fclose (file);
return 0;
}
In C, the "main" function is treated the same as every function, it has a return type (and in some cases accepts inputs via parameters). The only difference is that the main function is "called" by the operating system when the user runs the program. Thus the main function is always the first code executed when a program starts. main() function is a user defined, body of the function is defined by the programmer or we can say main() is programmer/user implemented function, whose prototype is predefined in the compiler. Hence we can say that main() in c programming is user defined as well as predefined because it's prototype is predefined. main() is a system (compiler) declared function whose defined by the user, which is invoked automatically by the operating system when program is being executed.
Closes a file descriptor, fildes. This frees the file descriptor to be returned by future open() calls and other calls that create file descriptors. The fildes argument must represent a hierarchical file system (HFS) file. When the last open file descriptor for a file is closed, the file itself is closed. If the file's link count is 0 at that time, its space is freed and the file becomes inaccessible. When the last open file descriptor for a pipe or FIFO file is closed, any data remaining in the pipe or FIFO file is discarded. close() unlocks (removes) all outstanding record locks that a process has on the associated file. Behavior for sockets: close() call shuts down the socket associated with the socket descriptor socket, and frees resources allocated to the socket. If socket refers to an open TCP connection, the connection is closed. If a stream socket is closed when there is input data queued, the TCP connection is reset rather than being cleanly closed.
Close file. Closes the file associated with the stream and disassociates it. All internal buffers associated with the stream are disassociated from it and flushed: the content of any unwritten output buffer is written and the content of any unread input buffer is discarded. Even if the call fails, the stream passed as parameter will no longer be associated with the file nor its buffers.
Open a temporary file. Creates a temporary binary file, open for update ("wb+" mode, see fopen for details) with a filename guaranteed to be different from any other existing file. The temporary file created is automatically deleted when the stream is closed (fclose) or when the program terminates normally. If the program terminates abnormally, whether the file is deleted depends on the specific system and library implementation. This function does not accept any parameter. If successful, the function returns a stream pointer to the temporary file created. On failure, NULL is returned.
#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program. Here are the two types of file that can be included using #include:
C file operations: Open, read, write and close operation in C. The fclose( ) function is used for closing an opened file. As argument you must provide a pointer to the file that you...
C program code ask the user for operation like insert, delete, display and exit. According to the option entered, access its respective function using switch statement and use the
