Metrologic Optimus R, Programming Manual

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Chapter 3 Terminal Specific Function Library 189
9 The value of count is negative.
10 No free file space for file extension.
See Also appendln, read, readln, write, writeln
appendln
Purpose To write a line (null-terminated string) to the bottom (EOF) of a DAT file.
Syntax int appendln (int fd, char *buffer);
int fd; /* file handle of the target DAT file */
char *buffer; /* pointer to a buffer where data is written to */
Example appendln (fd, data_buffer);
Description This routine writes a null-terminated string from the character array buffer to
the bottom of a DAT file ( fd ).
Characters are written to the file until a null character (\0) is encountered.
The null character is also written to the file.
Writing of data starts at the end-of-file position, and the file pointer
position is unaffected by the operation.
This routine will automatically extend the file size to hold the data written.
Return If successful, it returns the number of bytes actually written to the file,
including the null character.
On error, it returns -1.
An error code is set to the global variable fErrorCode to indicate the error
condition encountered. Below are possible error codes and their interpretation.
Error Code Interpretation
2 File specified by fd does not exist.
4 File specified by fd is not a DAT file.
7 Invalid file handle.
8 File not opened.
10 No free file space for file extension.
11 Cannot find string terminator in
buffer
.
See Also append, read, readln, write, writeln
chsize
Purpose To extend or truncate a DAT file.
Syntax int chsize (int fd, long size);