curs_inchstr - Linux

Overview

curs_inchstr() is a standard Linux ncurses library function that reads a character from the current cursor position and interprets it as a line drawing character. It’s commonly used in text-based user interfaces (TUIs) for creating borders, frames, and other decorative elements.

Syntax

chtype curs_inchstr(void);

Options/Flags

None.

Examples

Simple Character Retrieval

chtype ch = curs_inchstr();
if (ch == ACS_HLINE) {
    printf("Cursor is on a horizontal line character\n");
}

Drawing a Border

for (int i = 0; i < 80; i++) {
    mvaddch(0, i, curs_inchstr());  // Top border
    mvaddch(24, i, curs_inchstr()); // Bottom border
}
for (int i = 0; i < 25; i++) {
    mvaddch(i, 0, curs_inchstr());  // Left border
    mvaddch(i, 79, curs_inchstr()); // Right border
}

Common Issues

• Invalid Character: If the cursor is not positioned on a line drawing character, curs_inchstr() returns ERR.

Integration

curs_inchstr() can be used with other ncurses functions such as:

• mvaddch(): To display the retrieved character at a different location.
• attrset(): To modify the attributes (e.g., color, boldness) of the displayed character.

Related Commands

• curs_instr(): Reads the character at the cursor position without interpretation.
• box(): Draws a rectangular frame using line drawing characters.
• slk_attrset(): Sets the attributes of soft label keys.