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The C Users' Group Library 1994 August
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wc-cdrom-cusersgrouplibrary-1994-08.iso
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vol_100
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198_01
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buffer.c
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C/C++ Source or Header
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1990-01-23
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19KB
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624 lines
/*
* Buffer management.
* Some of the functions are internal,
* and some are actually attached to user
* keys. Like everyone else, they set hints
* for the display system.
*/
#include <stdio.h>
#include "estruct.h"
#include "edef.h"
BUFFER *getdefb() /* get the default buffer for a use or kill */
{
BUFFER *bp; /* default buffer */
/* Find the next buffer which will be the default */
bp = curbp->b_bufp;
/* cycle through the buffers to find an eligable one */
while (bp == NULL || (bp->b_flag & BFINVS)) {
if (bp == NULL) bp = bheadp;
else bp = bp->b_bufp;
/* don't get caught in an infinite loop! */
if (bp == curbp) {bp = NULL; break;}
}
return(bp);
}
/*
* Attach a buffer to a window. The
* values of dot and mark come from the buffer
* if the use count is 0. Otherwise, they come
* from some other window.
*/
usebuffer(f, n)
{
register BUFFER *bp;
#if BCOMPL
/* make a completion for a buffer name */
bp = getdefb();
bp = tenexbuf(TRUE, "Use buffer", bp ? bp->b_bname: "main");
if (!bp)
return(ABORT);
#else
register int s;
char bufn[NBUFN];
if ((s=mlreply("Use buffer: ", bufn, NBUFN)) != TRUE)
return (s);
if ((bp=bfind(bufn, TRUE, 0)) == NULL)
return (FALSE);
#endif
/* make it invisible if there is an argument */
if (f == TRUE)
if (n != 0) bp->b_flag |= BFINVS;
else bp->b_flag &= ~BFINVS;
return(swbuffer(bp));
}
nextbuffer(f, n) /* switch to the next buffer in the buffer list */
int f, n; /* default flag, numeric argument */
{
register BUFFER *bp; /* eligable buffer to switch to*/
register BUFFER *bbp; /* eligable buffer to switch to*/
int nbuffers;
/* make sure the arg is legit */
if (f == FALSE)
n = 1;
if (n < 1) {
/* return(FALSE); */
nbuffers = 0;
bp = bheadp;
while(bp != NULL) {
if (!(bp->b_flag & BFINVS)) ++nbuffers;
bp = bp->b_bufp;
}
if (nbuffers > 0) n = nbuffers - ((-n) % nbuffers);
}
bbp = curbp;
while (n-- > 0) {
/* advance to the next buffer */
bp = bbp->b_bufp;
/* cycle through the buffers to find an eligable one */
while (bp == NULL || bp->b_flag & BFINVS) {
if (bp == NULL)
bp = bheadp;
else
bp = bp->b_bufp;
/* don't get caught in an infinite loop! */
if (bp == bbp)
return(FALSE);
}
bbp = bp;
}
return(swbuffer(bp));
}
prevbuffer(f, n) /* switch to the previous buffer in the buffer list */
int f, n; /* default flag, numeric argument */
{
if (f == FALSE)
{ n = 1; f = TRUE; }
return( nextbuffer(f, -n) );
}
swbuffer(bp) /* make buffer BP current */
BUFFER *bp;
{
register WINDOW *wp;
if (--curbp->b_nwnd == 0) { /* Last use. */
curbp->b_dotp = curwp->w_dotp;
curbp->b_doto = curwp->w_doto;
curbp->b_markp = curwp->w_markp;
curbp->b_marko = curwp->w_marko;
curbp->b_fcol = curwp->w_fcol;
}
curbp = bp; /* Switch. */
if (curbp->b_active != TRUE) { /* buffer not active yet*/
/* read it in and activate it */
readin(curbp->b_fname, TRUE, FALSE);
curbp->b_dotp = lforw(curbp->b_linep);
curbp->b_doto = 0;
curbp->b_active = TRUE;
}
curwp->w_bufp = bp;
curwp->w_linep = bp->b_linep; /* For macros, ignored. */
curwp->w_flag |= WFMODE|WFFORCE|WFHARD; /* Quite nasty. */
if (bp->b_nwnd++ == 0) { /* First use. */
curwp->w_dotp = bp->b_dotp;
curwp->w_doto = bp->b_doto;
curwp->w_markp = bp->b_markp;
curwp->w_marko = bp->b_marko;
curwp->w_fcol = bp->b_fcol;
return (TRUE);
}
wp = wheadp; /* Look for old. */
while (wp != NULL) {
if (wp!=curwp && wp->w_bufp==bp) {
curwp->w_dotp = wp->w_dotp;
curwp->w_doto = wp->w_doto;
curwp->w_markp = wp->w_markp;
curwp->w_marko = wp->w_marko;
curwp->w_fcol = bp->b_fcol;
break;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* Dispose of a buffer, by name.
* Ask for the name. Look it up (don't get too
* upset if it isn't there at all!). Get quite upset
* if the buffer is being displayed. Clear the buffer (ask
* if the buffer has been changed). Then free the header
* line and the buffer header. Bound to "C-X K".
*/
killbuffer(f, n)
{
register BUFFER *bp;
#if BCOMPL
/* make a completion for a buffer name */
bp = getdefb();
bp = tenexbuf(TRUE, "Kill buffer", bp ? bp->b_bname: "main");
if (!bp) return(ABORT);
#else
register int s;
char bufn[NBUFN];
if ((s=mlreply("Kill buffer: ", bufn, NBUFN)) != TRUE)
return(s);
if ((bp=bfind(bufn, FALSE, 0)) == NULL) /* Easy if unknown. */
return (TRUE);
#endif
if(bp->b_flag & BFINVS) /* Deal with special buffers */
return (TRUE); /* by doing nothing. */
return(zotbuf(bp));
}
zotbuf(bp) /* kill the buffer pointed to by bp */
register BUFFER *bp;
{
register BUFFER *bp1;
register BUFFER *bp2;
register int s;
if (bp->b_nwnd != 0) { /* Error if on screen. */
mlwrite("Buffer is being displayed");
return (FALSE);
}
if ((s=bclear(bp)) != TRUE) /* Blow text away. */
return (s);
free((char *) bp->b_linep); /* Release header line. */
bp1 = NULL; /* Find the header. */
bp2 = bheadp;
while (bp2 != bp) {
bp1 = bp2;
bp2 = bp2->b_bufp;
}
bp2 = bp2->b_bufp; /* Next one in chain. */
if (bp1 == NULL) /* Unlink it. */
bheadp = bp2;
else
bp1->b_bufp = bp2;
free((char *) bp); /* Release buffer block */
return (TRUE);
}
namebuffer(f,n) /* Rename the current buffer */
int f, n; /* default Flag & Numeric arg */
{
register BUFFER *bp; /* pointer to scan through all buffers */
char bufn[NBUFN]; /* buffer to hold buffer name */
/* prompt for and get the new buffer name */
ask: if (mlreply("Change buffer name to: ", bufn, NBUFN) != TRUE)
return(FALSE);
/* and check for duplicates */
bp = bheadp;
while (bp != NULL) {
if (bp != curbp) {
/* if the names the same */
if (strcmp(bufn, bp->b_bname) == 0)
goto ask; /* try again */
}
bp = bp->b_bufp; /* onward */
}
strcpy(curbp->b_bname, bufn); /* copy buffer name to structure */
curwp->w_flag |= WFMODE; /* make mode line replot */
mlerase();
return(TRUE);
}
/*
List all of the active buffers. First update the special
buffer that holds the list. Next make sure at least 1
window is displaying the buffer list, splitting the screen
if this is what it takes. Lastly, repaint all of the
windows that are displaying the list. Bound to "C-X C-B".
A numeric argument forces it to list invisable buffers as
well.
*/
listbuffers(f, n)
{
register WINDOW *wp;
register BUFFER *bp;
register int s;
if ((s=makelist(f)) != TRUE)
return (s);
if (blistp->b_nwnd == 0) { /* Not on screen yet. */
if ((wp=wpopup()) == NULL)
return (FALSE);
bp = wp->w_bufp;
if (--bp->b_nwnd == 0) {
bp->b_dotp = wp->w_dotp;
bp->b_doto = wp->w_doto;
bp->b_markp = wp->w_markp;
bp->b_marko = wp->w_marko;
bp->b_fcol = wp->w_fcol;
}
wp->w_bufp = blistp;
++blistp->b_nwnd;
}
wp = wheadp;
while (wp != NULL) {
if (wp->w_bufp == blistp) {
wp->w_linep = lforw(blistp->b_linep);
wp->w_dotp = lforw(blistp->b_linep);
wp->w_doto = 0;
wp->w_markp = NULL;
wp->w_marko = 0;
wp->w_flag |= WFMODE|WFHARD;
}
wp = wp->w_wndp;
}
mlwrite("[Use ^X 1 to return to one window]");
return (TRUE);
}
/*
* This routine rebuilds the
* text in the special secret buffer
* that holds the buffer list. It is called
* by the list buffers command. Return TRUE
* if everything works. Return FALSE if there
* is an error (if there is no memory). Iflag
* indecates weather to list hidden buffers.
*/
makelist(iflag)
int iflag; /* list hidden buffer flag */
{
register char *cp1;
register char *cp2;
register int c;
register BUFFER *bp;
register LINE *lp;
register int s;
register int i;
long nbytes; /* # of bytes in current buffer */
char b[7+1];
char line[128];
blistp->b_flag &= ~BFCHG; /* Don't complain! */
if ((s=bclear(blistp)) != TRUE) /* Blow old text away */
return (s);
strcpy(blistp->b_fname, "");
if (addline("ACTN MODES Size Buffer File") == FALSE
|| addline("---- ----- ---- ------ ----") == FALSE)
return (FALSE);
bp = bheadp; /* For all buffers */
/* build line to report global mode settings */
cp1 = &line[0];
*cp1++ = ' ';
*cp1++ = ' ';
*cp1++ = ' ';
*cp1++ = ' ';
*cp1++ = ' ';
/* output the mode codes */
for (i = 0; i < NUMMODES; i++)
if (gmode & (1 << i))
*cp1++ = modecode[i];
else
*cp1++ = '.';
strcpy(cp1, " Global Modes");
if (addline(line) == FALSE)
return(FALSE);
/* output the list of buffers */
while (bp != NULL) {
/* skip invisable buffers if iflag is false */
if (((bp->b_flag&BFINVS) != 0) && (iflag != TRUE)) {
bp = bp->b_bufp;
continue;
}
cp1 = &line[0]; /* Start at left edge */
/* output status of ACTIVE flag (has the file been read in? */
if (bp->b_active == TRUE) /* "@" if activated */
*cp1++ = '@';
else
*cp1++ = ' ';
/* output status of changed flag */
if ((bp->b_flag&BFCHG) != 0) /* "*" if changed */
*cp1++ = '*';
else
*cp1++ = ' ';
/* output status of truncated flag */
if ((bp->b_flag&BFTRUNC) != 0) /* "#" if truncated */
*cp1++ = '#';
else
*cp1++ = ' ';
/* output status of narrowed flag */
if ((bp->b_flag&BFNAROW) != 0) /* "<" if narrowed */
*cp1++ = '<';
else
*cp1++ = ' ';
*cp1++ = ' '; /* Gap. */
/* output the mode codes */
for (i = 0; i < NUMMODES; i++) {
if (bp->b_mode & (1 << i))
*cp1++ = modecode[i];
else
*cp1++ = '.';
}
*cp1++ = ' '; /* Gap. */
nbytes = 0L; /* Count bytes in buf. */
lp = lforw(bp->b_linep);
while (lp != bp->b_linep) {
nbytes += (long)llength(lp)+1L;
lp = lforw(lp);
}
ltoa(b, 7, nbytes); /* 6 digit buffer size. */
cp2 = &b[0];
while ((c = *cp2++) != 0)
*cp1++ = c;
*cp1++ = ' '; /* Gap. */
cp2 = &bp->b_bname[0]; /* Buffer name */
while ((c = *cp2++) != 0)
*cp1++ = c;
cp2 = &bp->b_fname[0]; /* File name */
if (*cp2 != 0) {
while (cp1 < &line[4+1+5+1+6+1+NBUFN])
*cp1++ = ' ';
while ((c = *cp2++) != 0) {
if (cp1 < &line[128-1])
*cp1++ = c;
}
}
*cp1 = 0; /* Add to the buffer. */
if (addline(line) == FALSE)
return (FALSE);
bp = bp->b_bufp;
}
return (TRUE); /* All done */
}
ltoa(buf, width, num)
char buf[];
int width;
long num;
{
buf[width] = 0; /* End of string. */
while (num >= 10) { /* Conditional digits. */
buf[--width] = (int)(num%10L) + '0';
num /= 10L;
}
buf[--width] = (int)num + '0'; /* Always 1 digit. */
while (width != 0) /* Pad with blanks. */
buf[--width] = ' ';
}
/*
* The argument "text" points to
* a string. Append this line to the
* buffer list buffer. Handcraft the EOL
* on the end. Return TRUE if it worked and
* FALSE if you ran out of room.
*/
addline(text)
char *text;
{
register LINE *lp;
register int i;
register int ntext;
ntext = strlen(text);
if ((lp=lalloc(ntext)) == NULL)
return (FALSE);
for (i=0; i<ntext; ++i)
lputc(lp, i, text[i]);
blistp->b_linep->l_bp->l_fp = lp; /* Hook onto the end */
lp->l_bp = blistp->b_linep->l_bp;
blistp->b_linep->l_bp = lp;
lp->l_fp = blistp->b_linep;
if (blistp->b_dotp == blistp->b_linep) /* If "." is at the end */
blistp->b_dotp = lp; /* move it to new line */
return (TRUE);
}
/*
* Look through the list of
* buffers. Return TRUE if there
* are any changed buffers. Buffers
* that hold magic internal stuff are
* not considered; who cares if the
* list of buffer names is hacked.
* Return FALSE if no buffers
* have been changed.
*/
anycb()
{
register BUFFER *bp;
bp = bheadp;
while (bp != NULL) {
if ((bp->b_flag&BFINVS)==0 && (bp->b_flag&BFCHG)!=0)
return (TRUE);
bp = bp->b_bufp;
}
return (FALSE);
}
/*
* Find a buffer, by name. Return a pointer
* to the BUFFER structure associated with it.
* If the buffer is not found
* and the "cflag" is TRUE, create it. The "bflag" is
* the settings for the flags in in buffer.
*/
BUFFER *
bfind(bname, cflag, bflag)
register char *bname;
{
register BUFFER *bp;
register BUFFER *sb; /* buffer to insert after */
register LINE *lp;
char *malloc();
bp = bheadp;
while (bp != NULL) {
if (strcmp(bname, bp->b_bname) == 0)
return (bp);
bp = bp->b_bufp;
}
if (cflag != FALSE) {
if ((bp=(BUFFER *)malloc(sizeof(BUFFER))) == NULL)
return (NULL);
if ((lp=lalloc(0)) == NULL) {
free((char *) bp);
return (NULL);
}
/* find the place in the list to insert this buffer */
if (bheadp == NULL || strcmp(bheadp->b_bname, bname) > 0) {
/* insert at the beginning */
bp->b_bufp = bheadp;
bheadp = bp;
} else {
sb = bheadp;
while (sb->b_bufp != NULL) {
if (strcmp(sb->b_bufp->b_bname, bname) > 0)
break;
sb = sb->b_bufp;
}
/* and insert it */
bp->b_bufp = sb->b_bufp;
sb->b_bufp = bp;
}
/* and set up the other buffer fields */
bp->b_topline = NULL;
bp->b_botline = NULL;
bp->b_active = TRUE;
bp->b_dotp = lp;
bp->b_doto = 0;
bp->b_markp = NULL;
bp->b_marko = 0;
bp->b_fcol = 0;
bp->b_flag = bflag;
bp->b_mode = gmode;
bp->b_nwnd = 0;
bp->b_linep = lp;
strcpy(bp->b_fname, "");
strcpy(bp->b_bname, bname);
bp->b_fmode = 0666;
#if VMS
bp->b_fab_rfm = 2; /* FAB$C_VAR */
bp->b_fab_rat = 2; /* FAB$M_CR */
#endif
#if CRYPT
bp->b_key[0] = 0;
#endif
lp->l_fp = lp;
lp->l_bp = lp;
}
return (bp);
}
/*
* This routine blows away all of the text
* in a buffer. If the buffer is marked as changed
* then we ask if it is ok to blow it away; this is
* to save the user the grief of losing text. The
* window chain is nearly always wrong if this gets
* called; the caller must arrange for the updates
* that are required. Return TRUE if everything
* looks good.
*/
bclear(bp)
register BUFFER *bp;
{
register LINE *lp;
register int s;
if ((bp->b_flag&BFINVS) == 0 /* Not scratch buffer. */
&& (bp->b_flag&BFCHG) != 0 /* Something changed */
&& (s=mlyesno("Discard changes")) != TRUE)
return (s);
bp->b_flag &= ~BFCHG; /* Not changed */
while ((lp=lforw(bp->b_linep)) != bp->b_linep)
lfree(lp);
bp->b_dotp = bp->b_linep; /* Fix "." */
bp->b_doto = 0;
bp->b_markp = NULL; /* Invalidate "mark" */
bp->b_marko = 0;
bp->b_fcol = 0;
return (TRUE);
}
unmark(f, n) /* unmark the current buffers change flag */
int f, n; /* unused command arguments */
{
curbp->b_flag &= ~BFCHG;
upmode();
return(TRUE);
}
#if CALLABLE
frallbuffers() /* free all buffers */
{
while (bheadp != NULL) {
bheadp->b_flag &= ~BFCHG; /* clear changed mark */
if (zotbuf(bheadp) == FALSE) break;
}
}
#endif