Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : PCCAPP.ZIP
Filename : LINE.H

// line.h: Defines the class Line.
const MAXLINE = 160; // Maximum number of characters in a line.
const ENDCHAR = '#'; // Character to signify end of line.

class Line
{
// This class represents a line of text. Operations are provided to read
// and write the text, and also to compare lines.
public:
// Initialize my line - set it empty.
Line () { length = 0; }
// Repeatedly read characters from "in" and write them into my line
// until a newline or ENDCHAR is read. Set "end" to true if a newline has
// been read. Return the number of characters read, not counting the
// newline. My old line is wiped out before reading any characters.
// Will not work if there are more than MAXLINE characters to be read.
int ReadfromKeyboard (InputStream *in, int &end);
// Repeatedly read characters from "in" and write them into my line
// until a newline or ENDCHAR is read, or until there are no more
// characters to be read. Set "end" to true if a newline has
// been read. Return the number of characters read, not counting the
// newline. My old line is wiped out before reading any characters.
// Will not work if there are more than MAXLINE characters to be read.
int ReadfromFile (ReadFileStream *in, int &end);
// Write my line and a newline to "out". Return the number of characters
// written, including the newline.
int WriteToScreen (OutputStream *out);
// Write my line and a newline to "out". Return the number of characters
// written, including the newline.
int WriteToFile (WriteFileStream *out);
// Return the length of my line, not counting the newline at the end.
int Length () { return length; }
// Return true if l1 has the same contents as l2.
friend int equal (Line *l1, Line *l2);
private:
char linechar [MAXLINE]; // The characters in my line.
int length; // The number of characters in my line, not counting newline.
};

inline int equal (Line *l1, Line *l2)
{
// This function returns true if lines l1 and l2 are equal, that is, they
// have the same length and all their characters are equal.
if (l1 -> Length () != l2 -> Length ())
return 0;
else
{
int len = l1 -> Length ();
for (int i = 0; i < len; i++)
if (l1 -> linechar [i] != l2 -> linechar [i])
return 0;
return 1;
}
}