c Program to Copy Contents of One File to Another

// Program to Copy Contents of One File to Another
#include <stdio.h>
main()
{
FILE *fp1, *fp2;
char ch;
fp1 = fopen("abc.txt", "r");
fp2 = fopen("xyz.txt", "w");
while((ch = getc(fp1)) != EOF)
putc(ch, fp2);
fclose(fp1);
fclose(fp2);
getch();
}

 putc(), fputc(), putchar()

Write a single character to the console or to a file.

Prototypes

#include <stdio.h>

int putc(int c, FILE *stream);
int fputc(int c, FILE *stream);
int putchar(int c);

Description

All three functions output a single character, either to the console or to a FILE.
putc() takes a character argument, and outputs it to the specified FILE. fputc() does exactly the same thing, and differs from putc() in implementation only. Most people use fputc().
putchar() writes the character to the console, and is the same as calling putc(c, stdout).

fclose

int fclose ( FILE * stream );

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.

Parameters

stream

Pointer to a FILE object that specifies the stream to be closed.

fopen

FILE * fopen ( const char * filename, const char * mode );

Open file

Opens the file whose name is specified in the parameter filename and associates it with a stream that can be identified in future operations by the FILE pointer returned.

The operations that are allowed on the stream and how these are performed are defined by the mode parameter.

The returned stream is fully buffered by default if it is known to not refer to an interactive device (see setbuf).

The returned pointer can be disassociated from the file by calling fclose or freopen. All opened files are automatically closed on normal program termination.

The running environment supports at least FOPEN_MAX files open simultaneously.

Parameters

filename

C string containing the name of the file to be opened.
Its value shall follow the file name specifications of the running environment and can include a path (if supported by the system).

mode

C string containing a file access mode. It can be:

"r"	read: Open file for input operations. The file must exist.
"w"	write: Create an empty file for output operations. If a file with the same name already exists, its contents are discarded and the file is treated as a new empty file.
"a"	append: Open file for output at the end of a file. Output operations always write data at the end of the file, expanding it. Repositioning operations (fseek, fsetpos, rewind) are ignored. The file is created if it does not exist.
"r+"	read/update: Open a file for update (both for input and output). The file must exist.
"w+"	write/update: Create an empty file and open it for update (both for input and output). If a file with the same name already exists its contents are discarded and the file is treated as a new empty file.
"a+"	append/update: Open a file for update (both for input and output) with all output operations writing data at the end of the file. Repositioning operations (fseek, fsetpos, rewind) affects the next input operations, but output operations move the position back to the end of file. The file is created if it does not exist.