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Unformatted text preview: , the file must be closed using this
operation. 5. Read. Is used to read data stored in a file.
6. Write. Is used to write new data in a file.
7. Seek. This operation is used with random access files to first position the
read/write pointer to a specific place in the file, so that data can be read from, or
written to, that position.
8. Get attributes. Is used to access the attributes of a file.
9. Set attributes. Is used to change the user-settable attributes (such as, protection
mode) of a file.
10. Rename. Is used to change the name of an existing file.
11. Copy. Is used to create a copy of a file, or to copy a file to an I/O device such
as a printer or a display.
When a file is created, it is given a name, which can be later used to access the
file. The rules for naming files vary from one operating system to another. For
instance, consider the following examples:
1. MS-DOS allows only up to 8 characters for a file name, Macintosh allows up
to 31 characters, and Microsoft Windows allows up to 255 characters.
longer file names, users have greater flexibility in assigning more descriptive and
meaningful names to their files.
Some operating systems allow only letters and numbers to be used in file
names, whereas others also allow special characters (sometimes barring a few) to
be used in file names. Hence names like letter3 Jrom Ram, reminder2_to_Sham
are often valid file names.
3. Some operating systems (such as Unix) distinguish between upper case letters
and lower case letters, whereas others (such as MS-DOS) do not. Thus the file
names Sinha, sinha and SINHA will be treated as different and can be assigned to
three different files in Unix, but they will be treated as same in MS-DOS and
cannot be assigned to three different files.
4. Many operating systems support file names having two or more parts, with the
different parts separated by a period. For example, MS-DOS supports two-part file
names in which the first part can have 1 to 8 characters, and the optional second
part can have 1 to 3 characters (such as letter.txt). In Unix, a file may have more
than two parts, as...
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This document was uploaded on 04/07/2014.
- Spring '14