♠ Posted by Unknown in C'Language at 01:18
File Management Functions:
1. fopen():
The fopen() function is used to open a file.
Syntax:
<filepointer>
= fopen(<”filename”>, <”open mode”>);
“filepointer” is the name of the file pointer that has
been defined earlier.
“filename” is the name of the file that is to be opened.
If a constant value is to be supplied as a file name, it is enclosed with in
double quote marks “ “. A file name can also be supplied as a string variable
argument.
“open mode” is the mode in which the file is to be
opened. Various modes in which a file can be opened are.
1. “w” write
mode
2. “r” read mode
3. “a” append mode
4. “w+” write-read mode
5. “r+” read-write mode
6. “a+” append or create new
2. fclose():
The fclose() function is used to close
a previously opened file.
Syntax:
fclose(<filepointer>);
“filepointer” contains the return
value of the corresponding fopen() function when the specified file was opened.
3. putc():
To write data into a file character by
character, we make use of the putc() standard function in ‘C’. putc() function
is analogous to the putchar() function.
Syntax:
putc(<character
variable>, <filepointer>);
“character variable” contains the
character which one wants to write to the file, which has already been opened
in a mode that supports writing to file. This function is used when this file
must be opened in write or append mode. Another function which has been used to
write data into a file character by character is the fputc() function. fputc()
and putc() function work in exactly the same manner.
Syntax:
fputc(<character
variable>, <filepointer>);
4. getc():
To read a file character by character,
we make use of the getc() standard function in ‘C’. getc() function is
analogous to the getchar() function.
Syntax:
<character
variable> = getc(<file pointer>);
“character variable” is one which we
want to read a character from the file that has already been opened in a mode
that supports the reading operation. This function is used when file is opened
in read mode or read-write mode. ‘C’ also provides another function fgetc() to
read a file character by character.
Syntax:
<character
variable> = fgetc(<file pointer>);
5. feof():
‘C’ provides the feof() function,
which returns the value true (non zero) if the end of file has been reached or
returns false (zero).
Syntax:
feof(<filepointer>);
6. fprintf():
The fprintf() function is similar to
printf() function. the printf() function is used for formatted output on the
standard output device. In a similar manner the fprintf() function is used for
formatted output to files.
Syntax:
fprintf(<filepointer>,
<format specifier>, <variables>);
7. fscanf():
The fscanf() function is similar to
the scanf() function. the scanf() function is used for formatted input from the
standard input device. In a similar manner the fscanf() function is used for
formatted input from files.
Syntax:
fscanf(<filepointer>,
<format specifier>, <variables>);
8. fputs():
fputs() function is similar to puts()
function. it writes a string into the file and places the new line character
after writing a line in the file.
Syntax:
fputs(<string>,
<filepointer>);
“string” is the character array that
contains the text that is to be written into the file, accessed by
“filepointer”.
9. fgets():
fgets() function is similar to gets()
function, and is used to read a sting of character from the file specified.
Syntax:
fgets(<string>,
<max_no_of_characters>, <file pointer>);
“string” is the name of the character
array into which the text will be read from the file.
“max_no_of_characters” specifies the
maximum number of character that will be read from the file when the function
is called. At any time max_no_of_characters-1 characters will be read from the
file and stored in string.
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