HP Pascal/iX Programmer's Guide (31502-90023)

ManualsBrandsHP ManualsSoftwareMPE/iX 6.0 Operating System

3- 18

readln(infile); {and advance to the next line.}

writeln(linepos(outfile)); {Also, print the number of characters

written to outfile,}

writeln(outfile); {and start a new line of outfile.}

END {IF} {If the current line of infile has not ended,}

ELSE BEGIN

read(in,c); {read the next character of infile,}

write(out,c); {and write it to outfile.}

END;

END; {WHILE}

END.

The preceding program copies the textfile infile to the

textfile outfile, writing the values of linepos(infile) and

linepos(outfile) to the standard textfile output whenever

eoln(infile) is

true

Except for the

position

function, every sequential I/O procedure and

sequential file function applies to textfiles (see "Sequential

Input/Output" ). Sequential files work the same way, except that for

textfiles, read (like readln) sometimes performs implicit data

conversion, and write (like writeln) can format the output value. See

the

HP Pascal/iX Reference Manual

or the

HP Pascal/HP-UX Reference

Manual

, depending on your implementation, for information on implicit

data conversion and formatting output values.

Direct Input/Output

Direct input/output

is input/output that is performed with direct files;

that is, files whose current position indices can be manipulated directly

by the program. Direct input and output come from read-write files

opened by the procedure open (they cannot be textfiles). Your program

can use the same direct file for input and output.

Table 3-8 summarizes the characteristics of the predefined direct I/O

procedures. (The I/O procedures in Table 3-3 also work on direct

access files.)

Table 3-8. Characteristics of Direct I/O Procedures

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| Procedure |

Readdir

Writedir

Seek

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| State that | Read-write |

| file must be in | |

|| |

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| Advances current | To component following specified component | To specified |

| position index | | component |

|| ||

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| After call, | No | Yes |

| buffer is | | |

| undefined | | |

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