DREAD/DXREA

These routines read data from your file (currently open to the Data Control Block) into your program's data buffer. DREAD is equivalent to the FMGR call READF; DXREA is equivalent to EREAD.

DREAD(dcb,err,buf,len[,rlen][,num][,erlc])

DXREA(dcb,err,buf,len[,rlen][,num][,erlc])

dcb

Four-word array. Data Control Block. (See •RFA

(input/output)

Common Parameters" for more information.)

err

16-bit integer. Error return variable. (See •RFA

 

Common Parameters" for more information.)

buf

Integer array (FORTRAN); Packed character

 

array (PASCAL). Data buffer. An array, with a size equal

 

to or greater than the value of the len parameter, into which

 

the requested data is placed by the system.

len

16-bit integer. Data length. A variable specifying the

 

number of words to be read. (See •RFA Common Parameters"

 

for more information.)

rlen

16-bit integer. Actual length (in words) of data read. A

 

variable to which the actual count of words transferred is

 

returned. Set to -1 if endoffile is read.

num

16-bit integer/32-bit integer. Record number. A

 

variable that, if positive, contains the record number from

 

which data is to be read. If negative, num is the number of

 

records to backspace. If omitted, the record at the current

 

position is read. Meaningful for type 1 and type 2 files only.

 

For DXREA, num is a doubleword variable >32767.

erlc

16-bit integer. Error condition location. (See •RFA

 

Common Parameters" for more information.)

1012 Remote File Access