Read from file but not move pointer

[John]

Guys,

As title says, I need to read from a file but don't want to move the
file pointer. I know I can use rewind or fseek to move back in file but
is there a function that allows you to read but not actually move the
file pointer (or auto reset the pointer back to original pre read position)?

Cheers,

John.

 

[Roland Pibinger]

As title says, I need to read from a file but don't want to move the
file pointer. I know I can use rewind or fseek to move back in file but
is there a function that allows you to read but not actually move the
file pointer (or auto reset the pointer back to original pre read position)?

Write a reusable function that does what you want using fread, ftell,
fseek.

 

[Jeffrey Baker]

Guys,

As title says, I need to read from a file but don't want to move the file
pointer. I know I can use rewind or fseek to move back in file but is
there a function that allows you to read but not actually move the file
pointer (or auto reset the pointer back to original pre read position)?

Cheers,

John.

What about seekg( n, io:cur) should keep it in position once there when n is
set to 0.

 

[James Kanze]

As title says, I need to read from a file but don't want to
move the file pointer. I know I can use rewind or fseek to
move back in file but is there a function that allows you to
read but not actually move the file pointer (or auto reset the
pointer back to original pre read position)?

By definition, it wouldn't be a stream if the pointer didn't
advance. (FWIW, I don't know of an OS which provides this
functionality either.) The only solution is to use tellg() to
get the original position, and then seekg() to return to it.