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Move terminal escape sequence handling into a function and reuse in c… #230

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241 changes: 123 additions & 118 deletions linenoise.c
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Original file line number Diff line number Diff line change
Expand Up @@ -374,70 +374,6 @@ static void refreshLineWithCompletion(struct linenoiseState *ls, linenoiseComple
if (lc != &ctable) freeCompletions(&ctable);
}

/* This is an helper function for linenoiseEdit*() and is called when the
* user types the <tab> key in order to complete the string currently in the
* input.
*
* The state of the editing is encapsulated into the pointed linenoiseState
* structure as described in the structure definition.
*
* If the function returns non-zero, the caller should handle the
* returned value as a byte read from the standard input, and process
* it as usually: this basically means that the function may return a byte
* read from the termianl but not processed. Otherwise, if zero is returned,
* the input was consumed by the completeLine() function to navigate the
* possible completions, and the caller should read for the next characters
* from stdin. */
static int completeLine(struct linenoiseState *ls, int keypressed) {
linenoiseCompletions lc = { 0, NULL };
int nwritten;
char c = keypressed;

completionCallback(ls->buf,&lc);
if (lc.len == 0) {
linenoiseBeep();
ls->in_completion = 0;
} else {
switch(c) {
case 9: /* tab */
if (ls->in_completion == 0) {
ls->in_completion = 1;
ls->completion_idx = 0;
} else {
ls->completion_idx = (ls->completion_idx+1) % (lc.len+1);
if (ls->completion_idx == lc.len) linenoiseBeep();
}
c = 0;
break;
case 27: /* escape */
/* Re-show original buffer */
if (ls->completion_idx < lc.len) refreshLine(ls);
ls->in_completion = 0;
c = 0;
break;
default:
/* Update buffer and return */
if (ls->completion_idx < lc.len) {
nwritten = snprintf(ls->buf,ls->buflen,"%s",
lc.cvec[ls->completion_idx]);
ls->len = ls->pos = nwritten;
}
ls->in_completion = 0;
break;
}

/* Show completion or original buffer */
if (ls->in_completion && ls->completion_idx < lc.len) {
refreshLineWithCompletion(ls,&lc,REFRESH_ALL);
} else {
refreshLine(ls);
}
}

freeCompletions(&lc);
return c; /* Return last read character */
}

/* Register a callback function to be called for tab-completion. */
void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
completionCallback = fn;
Expand Down Expand Up @@ -844,6 +780,128 @@ void linenoiseEditDeletePrevWord(struct linenoiseState *l) {
refreshLine(l);
}

void linenoiseHandleTerminalEscapeSequence(struct linenoiseState *l)
{
char seq[3];

/* Read the next two bytes representing the escape sequence.
* Use two calls to handle slow terminals returning the two
* chars at different times. */
if (read(l->ifd,seq,1) == -1) return ;
if (read(l->ifd,seq+1,1) == -1) return ;

/* ESC [ sequences. */
if (seq[0] == '[') {
if (seq[1] >= '0' && seq[1] <= '9') {
/* Extended escape, read additional byte. */
if (read(l->ifd,seq+2,1) == -1) return ;
if (seq[2] == '~') {
switch(seq[1]) {
case '3': /* Delete key. */
linenoiseEditDelete(l);
break;
}
}
} else {
switch(seq[1]) {
case 'A': /* Up */
linenoiseEditHistoryNext(l, LINENOISE_HISTORY_PREV);
break;
case 'B': /* Down */
linenoiseEditHistoryNext(l, LINENOISE_HISTORY_NEXT);
break;
case 'C': /* Right */
linenoiseEditMoveRight(l);
break;
case 'D': /* Left */
linenoiseEditMoveLeft(l);
break;
case 'H': /* Home */
linenoiseEditMoveHome(l);
break;
case 'F': /* End*/
linenoiseEditMoveEnd(l);
break;
}
}
}

/* ESC O sequences. */
else if (seq[0] == 'O') {
switch(seq[1]) {
case 'H': /* Home */
linenoiseEditMoveHome(l);
break;
case 'F': /* End*/
linenoiseEditMoveEnd(l);
break;
}
}
return ;
}

/* This is an helper function for linenoiseEdit*() and is called when the
* user types the <tab> key in order to complete the string currently in the
* input.
*
* The state of the editing is encapsulated into the pointed linenoiseState
* structure as described in the structure definition.
*
* If the function returns non-zero, the caller should handle the
* returned value as a byte read from the standard input, and process
* it as usually: this basically means that the function may return a byte
* read from the termianl but not processed. Otherwise, if zero is returned,
* the input was consumed by the completeLine() function to navigate the
* possible completions, and the caller should read for the next characters
* from stdin. */
static int completeLine(struct linenoiseState *ls, int keypressed) {
linenoiseCompletions lc = { 0, NULL };
int nwritten;
char c = keypressed;

completionCallback(ls->buf,&lc);
if (lc.len == 0) {
linenoiseBeep();
ls->in_completion = 0;
} else {
switch(c) {
case TAB: /* tab */
if (ls->in_completion == 0) {
ls->in_completion = 1;
ls->completion_idx = 0;
} else {
ls->completion_idx = (ls->completion_idx+1) % (lc.len+1);
if (ls->completion_idx == lc.len) linenoiseBeep();
}
c = 0;
break;
default:
/* Update buffer and return */
if (ls->completion_idx < lc.len) {
nwritten = snprintf(ls->buf,ls->buflen,"%s",
lc.cvec[ls->completion_idx]);
ls->len = ls->pos = nwritten;
}
ls->in_completion = 0;
if (c == ESC) {
linenoiseHandleTerminalEscapeSequence(ls);
c = 0;
}
break;
}

/* Show completion or original buffer */
if (ls->in_completion && ls->completion_idx < lc.len) {
refreshLineWithCompletion(ls,&lc,REFRESH_ALL);
} else {
refreshLine(ls);
}
}

freeCompletions(&lc);
return c; /* Return last read character */
}

/* This function is part of the multiplexed API of Linenoise, that is used
* in order to implement the blocking variant of the API but can also be
* called by the user directly in an event driven program. It will:
Expand Down Expand Up @@ -932,7 +990,6 @@ char *linenoiseEditFeed(struct linenoiseState *l) {

char c;
int nread;
char seq[3];

nread = read(l->ifd,&c,1);
if (nread <= 0) return NULL;
Expand Down Expand Up @@ -1002,59 +1059,7 @@ char *linenoiseEditFeed(struct linenoiseState *l) {
linenoiseEditHistoryNext(l, LINENOISE_HISTORY_NEXT);
break;
case ESC: /* escape sequence */
/* Read the next two bytes representing the escape sequence.
* Use two calls to handle slow terminals returning the two
* chars at different times. */
if (read(l->ifd,seq,1) == -1) break;
if (read(l->ifd,seq+1,1) == -1) break;

/* ESC [ sequences. */
if (seq[0] == '[') {
if (seq[1] >= '0' && seq[1] <= '9') {
/* Extended escape, read additional byte. */
if (read(l->ifd,seq+2,1) == -1) break;
if (seq[2] == '~') {
switch(seq[1]) {
case '3': /* Delete key. */
linenoiseEditDelete(l);
break;
}
}
} else {
switch(seq[1]) {
case 'A': /* Up */
linenoiseEditHistoryNext(l, LINENOISE_HISTORY_PREV);
break;
case 'B': /* Down */
linenoiseEditHistoryNext(l, LINENOISE_HISTORY_NEXT);
break;
case 'C': /* Right */
linenoiseEditMoveRight(l);
break;
case 'D': /* Left */
linenoiseEditMoveLeft(l);
break;
case 'H': /* Home */
linenoiseEditMoveHome(l);
break;
case 'F': /* End*/
linenoiseEditMoveEnd(l);
break;
}
}
}

/* ESC O sequences. */
else if (seq[0] == 'O') {
switch(seq[1]) {
case 'H': /* Home */
linenoiseEditMoveHome(l);
break;
case 'F': /* End*/
linenoiseEditMoveEnd(l);
break;
}
}
linenoiseHandleTerminalEscapeSequence(l);
break;
default:
if (linenoiseEditInsert(l,c)) return NULL;
Expand Down