|Command||basic.%read C Function/BASIC Program
Applicable release versions: AP/Unix
|Category||BASIC Program (486)|
|Description||reads the number of bytes designated in "size" into the "variable", from the file specified by "file.descriptor" returned by a previous call to "%open()", "%creat()" or "dup()".
A string of a size at least equal to "size" must have been assigned to "variable" before the call by either an explicit assignment (eg buffer=space(1000)) or by the "char" reserve statement, or else the data is truncated.
This function returns the number of bytes actually read. If less than "size" bytes are returned, the content of the string beyond is undefined, as is usual in C. No data translation occurs. If the data read in variable contains Segment Marks (x'ff'), results are unpredictable. Use "%malloc()" to obtain a Unix memory in which to read binary data.
|Syntax||n=%read(file.descriptor, variable, size)|
item='' char buffer ;* reserve buffer space loop while true do n=%read(fd, buffer, 10000) if n=-1 then print "Error ":system(0) stop end else if n<10000 then * The whole file has been read. item=item:buffer[1,n] convert char(10) to char(254) in item write item on itemname stop end else * Some more to read item=item:buffer end end repeat