.TH sc_read_record 3 "April 2003" "OpenSC Programmer's Manual
.SH NAME
sc_read_record, sc_write_record, sc_update_record \- read and write files on a smart card
.SH SYNOPSIS
.nf
.B #include <opensc.h>
.sp
.BI "int sc_read_record(sc_card_t *" card ",
.BI "                   unsigned int " rec_nr ",
.BI "                   unsigned char *" buffer ",
.BI "                   size_t " count ",
.BI "                   unsigned long " flags ");
.BI "int sc_write_record(sc_card_t *" card ",
.BI "                   unsigned int " rec_nr ",
.BI "                   const unsigned char *" buffer ",
.BI "                   size_t " count ",
.BI "                   unsigned long " flags ");
.BI "int sc_update_record(sc_card_t *" card ",
.BI "                   unsigned int " rec_nr ",
.BI "                   const unsigned char *" buffer ",
.BI "                   size_t " count ",
.BI "                   unsigned long " flags ");
.BI "int sc_append_record(sc_card_t *" card ",
.BI "                   const unsigned char *" buffer ",
.BI "                   size_t " count ",
.BI "                   unsigned long " flags ");
.fi
.SH DESCRIPTION
This functions read and write record-structured elementary files
(EFs) on a smart card. The correspond to the ISO 7816 functions READ
RECORD, WRITE RECORD, APPEND RECORD and UPDATE RECORD, respectively.
(The difference between write and update is that the former means writing
to an uninitialized file, while the latter is intended to update a record
previously written to - some card have different access conditions for
these operations).
.PP
The \fIrec_nr\fP argument specifies the number of the record to be
written to, starting at 0.
.PP
The \fIflags\fP argument is currently not used, and should be set
to 0.
.SH RETURN VALUE
If an error occurred, a negative error code is returned, as described
in \fbsc_error\fP(3). Otherwise, the function will return the
number of bytes read or written.
.SH SEE ALSO
.BR sc_file (3),
.BR sc_path (3),
.BR sc_establish_context (3),
.BR sc_select_file (3),
.BR sc_read_binary (3),
.BR sc_delete_file (3),
.BR sc_create_file (3),
.BR sc_file_free (3).
.SH AUTHOR
This manual page was written by Olaf Kirch <okir@suse.de>