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/* $Id: pltek.c,v 1.10 2001/01/10 06:45:32 mlebrun Exp $
*
* Review a Tektronix vector file.
* from 'scan', by Clair Nielsen, LANL.
* Modifications by Maurice LeBrun, IFS.
*
* This version works well with xterm and at least one vt100/tek emulator
* I've tried.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
static void describe(void);
static void tek_mode(int mode);
#define ESC 27 /* ESCape character */
#define ALPHA_MODE 0 /* switch to alpha mode */
#define GRAPH_MODE 1 /* switch to graph mode */
#define BUFSZ 1024
#define MAXPAGES 1024
enum { unknown, xterm, tekterm } termtype = unknown;
int
main(int argc, char *argv[])
{
FILE *fd;
int i, j, nb, npage, ipage, ifirst, oldpage;
int istop;
long start[MAXPAGES]; /* start (offset) of each page */
char buf[BUFSZ], xtra, lastchar = '\0';
char c, ibuf[128], *t;
if (argc < 2) {
describe();
exit(1);
}
if ((fd = fopen(argv[1], "r")) == NULL) {
printf("Cannot open %s\n", argv[1]);
exit(1);
}
if ( (t = getenv("TERM")) != NULL ) {
if ( strcmp("xterm", t) == 0 ) {
termtype = xterm;
} else if (!strncmp("tek",t,3) ||
!strncmp("401",t,3) ||
!strncmp("410",t,3) ) {
termtype = tekterm;
}
}
/* Find out how many pages there are in file. */
ipage = 0;
start[0] = 0;
for (i = 0; i < MAXPAGES; i++) {
nb = fread(buf, 1, BUFSZ, fd);
if (nb <= 0)
break;
ifirst = 0;
for (j = 0; j < nb; j++) {
if ((lastchar = buf[j]) == '\f') {
ifirst = j - 1;
ipage++;
start[ipage] = BUFSZ * i + ifirst + 2;
}
}
}
/* don't count a FF at the end of the file as a separate page */
if (lastchar == '\f')
ipage--;
npage = ipage + 1;
/* Loop until the user quits */
ipage = 0;
while (1) {
oldpage = ipage;
printf("Page %d/%d> ", ipage, npage);
if (!fgets(ibuf, 128, stdin))
break;
c = ibuf[0];
/* User input a page number or a return */
/* A carriage return in response to the prompt proceeds to the next page. */
if (c == '\n') { /* CR = increment by one page */
ipage++;
} else if (c == '+') { /* +<n> = increment by <n> pages */
ipage += atoi(ibuf+1);
} else if (c == '-') { /* -<n> = decrement by <n> pages */
ipage -= atoi(ibuf+1);
} else if (isdigit(c)) { /* <n> = goto page <n> */
ipage = atoi(ibuf);
} else if (c == '\f') {
; /* FF = redraw the last plot */
} else if (c == 'q') { /* q = quit */
break;
} else { /* h, ? or garbage = give help */
tek_mode(ALPHA_MODE);
describe();
continue;
}
/* Bounds checking */
if (ipage > npage) {
ipage = npage;
if (ipage == oldpage)
continue;
} else if (ipage < 0) {
ipage = 1;
} else if (ipage == 0) {
continue; /* page 0 does not exist */
}
/* Time to actually plot something. */
tek_mode(GRAPH_MODE);
istop = fseek(fd, start[ipage - 1], 0);
xtra = '\0';
istop = 0;
for (i = 0; i < 8196; i++) { /* less than 8MB per page! */
if (xtra) {
fwrite(&xtra, 1, 1, stdout);
xtra = '\0';
}
nb = fread(buf, 1, BUFSZ, fd);
if (nb <= 0)
break;
ifirst = 0;
for (j = 0; j < nb; j++) {
if (buf[j] == '\f') {
fwrite(&buf[ifirst], 1, j - ifirst, stdout);
fflush(stdout);
istop = 1;
break;
}
}
if (istop)
break;
if (buf[nb] == ESC) {
xtra = ESC;
j--;
}
fwrite(&buf[ifirst], 1, j - ifirst, stdout);
}
if ( termtype == xterm )
tek_mode(ALPHA_MODE);
}
tek_mode(ALPHA_MODE); /* how to kill an xterm Tek window? */
fclose(fd);
exit(0);
}
/*----------------------------------------------------------------------*\
* tek_mode()
*
* switch to alpha/graph mode
\*----------------------------------------------------------------------*/
static int currentmode = ALPHA_MODE;
static void
tek_mode (int mode)
{
if ( mode == GRAPH_MODE ) {
if ( currentmode == ALPHA_MODE ) {
switch(termtype) {
case tekterm:
break;
case xterm:
printf("\033[?38h"); /* open graphics window */
break;
default:
printf("\033[?38h"); /* open graphics window */
}
printf("\035"); /* Enter Vector mode = GS */
}
printf("\033\f"); /* clear screen = ESC FF */
fflush(stdout);
currentmode = mode;
} else if ( mode == ALPHA_MODE ) {
switch(termtype) {
case tekterm:
printf("\037\030"); /* Enter Alpha mode = US CAN */
break;
case xterm:
printf("\033\003"); /* VT mode (xterm) = ESC ETX */
break;
default:
printf("\033\003"); /* VT mode (xterm) = ESC ETX */
}
fflush(stdout);
currentmode = mode;
}
}
/*----------------------------------------------------------------------*\
* describe()
*
* Print help message.
* Note: if this message starts to exceed 512 bytes, may need to split
* since some compilers can't handle strings that long.
\*----------------------------------------------------------------------*/
static void
describe (void)
{
fputs("\
Usage: pltek filename \n\
At the prompt, the following replies are recognized:\n\
h,? Give this help message.\n\
q Quit program.\n\
<n> Go to the specified page number.\n\
-<n> Go back <n> pages.\n\
+<n> Go forward <n> pages.\n\
<Return> Go to the next page.\n\n",
stdout);
}
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