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kgets - putch(ch buf[pos = ch else if(ch==\b ||...

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#include <types.h> #include <lib.h> /* * Do a backspace in typed input. * We overwrite the current character with a space in case we're on * a terminal where backspace is nondestructive. */ static void backsp(void) { putch('\b'); putch(' '); putch('\b'); } /* * Read a string off the console. Support a few of the more useful * common control characters. Do not include the terminating newline * in the buffer passed back. */ void kgets(char *buf, size_t maxlen) { size_t pos = 0; int ch; while (1) { ch = getch(); if (ch=='\n' || ch=='\r') { putch('\n'); break; } /* Only allow the normal 7-bit ascii */ if (ch>=32 && ch<127 && pos < maxlen-1) {
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Unformatted text preview: putch(ch); buf[pos++] = ch; } else if ((ch=='\b' || ch==127) && pos>0) { /* backspace */ backsp(); pos--; } else if (ch==3) { /* ^C - return empty string */ putch('^'); putch('C'); putch('\n'); pos = 0; break; } else if (ch==18) { /* ^R - reprint input */ buf[pos] = 0; kprintf("^R\n%s", buf); } else if (ch==21) { /* ^U - erase line */ while (pos > 0) { backsp(); pos--; } } else if (ch==23) { /* ^W - erase word */ while (pos > 0 && buf[pos-1]==' ') { backsp(); pos--; } while (pos > 0 && buf[pos-1]!=' ') { backsp(); pos--; } } else { beep(); } } buf[pos] = 0; }...
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