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calc/help/ftell
2017-05-21 15:38:25 -07:00

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NAME
ftell - return a file position
SYNOPSIS
ftell(fd)
TYPES
fd open file stream
return non-negative integer or error value
DESCRIPTION
This function attempts to return the current value of the file position
indicator for the stream. This is the number of characters (bytes)
between the beginning of the file and the position of the
next character for output in "w" or "w+" mode or for input.
On failure, this returns an error value.
EXAMPLE
> fd = fopen("/tmp/curds", "w")
> fputs(fd, "0123456789")
> ftell(fd)
10
> fputs(fd, "abcdef")
> ftell(fd)
16
> fseek(fd, 20, 0)
> ftell(fd)
20
> fputs(fd, "01234")
> ftell(fd)
25
> freopen(fd, "r")
> fscanf(fd, "%*5c")
0
> ftell(fd)
5
LIMITS
none
LIBRARY
none
SEE ALSO
fseek, fgetpos, fsetpos, rewind, strerror