std.c

   1 #include <sys/ioctl.h>
   2 #include <sys/select.h>
   3 #include <sys/stat.h>
   4 #include <sys/types.h>
   5 #include <sys/wait.h>
   6 #include <ctype.h>
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <signal.h>
  10 #include <stdarg.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <unistd.h>
  15
  16 #define LENGTH(x)       (sizeof(x) / sizeof((x)[0]))
  17 #define MAX(a,b)        (((a) > (b)) ? (a) : (b))
  18 #define MIN(a,b)        (((a) < (b)) ? (a) : (b))
  19
  20 void buffer(char c);
  21 void cmd(const char *cmdstr, ...);
  22 void *emallocz(unsigned int size);
  23 void eprint(const char *errstr, ...);
  24 void eprintn(const char *errstr, ...);
  25 void getpty(void);
  26 void movea(int x, int y);
  27 void mover(int x, int y);
  28 void parse(void);
  29 void scroll(int l);
  30 void shell(void);
  31 void sigchld(int n);
  32 char unbuffer(void);
  33
  34 typedef struct {
  35         unsigned char data[BUFSIZ];
  36         int s, e;
  37         int n;
  38 } RingBuffer;
  39
  40 int cols = 80, lines = 25;
  41 int cx = 0, cy = 0;
  42 int c;
  43 FILE *fptm = NULL;
  44 int ptm, pts;
  45 _Bool bold, digit, qmark;
  46 pid_t pid;
  47 RingBuffer buf;
  48
  49 void
  50 buffer(char c) {
  51         if(buf.n < LENGTH(buf.data))
  52                 buf.n++;
  53         else
  54                 buf.s = (buf.s + 1) % LENGTH(buf.data);
  55         buf.data[buf.e++] = c;
  56         buf.e %= LENGTH(buf.data);
  57 }
  58
  59 void
  60 cmd(const char *cmdstr, ...) {
  61         va_list ap;
  62
  63         putchar('\n');
  64         putchar(':');
  65         va_start(ap, cmdstr);
  66         vfprintf(stdout, cmdstr, ap);
  67         va_end(ap);
  68 }
  69
  70 void *
  71 emallocz(unsigned int size) {
  72         void *res = calloc(1, size);
  73
  74         if(!res)
  75                 eprint("fatal: could not malloc() %u bytes\n", size);
  76         return res;
  77 }
  78
  79 void
  80 eprint(const char *errstr, ...) {
  81         va_list ap;
  82
  83         va_start(ap, errstr);
  84         vfprintf(stderr, errstr, ap);
  85         va_end(ap);
  86         exit(EXIT_FAILURE);
  87 }
  88
  89 void
  90 eprintn(const char *errstr, ...) {
  91         va_list ap;
  92
  93         va_start(ap, errstr);
  94         vfprintf(stderr, errstr, ap);
  95         va_end(ap);
  96         fprintf(stderr, ": %s\n", strerror(errno));
  97         exit(EXIT_FAILURE);
  98 }
  99
 100 void
 101 getpty(void) {
 102         char *ptsdev;
 103
 104 #if defined(_GNU_SOURCE)
 105         ptm = getpt();
 106 #elif _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
 107         ptm = posix_openpt(O_RDWR);
 108 #else
 109         ptm = open("/dev/ptmx", O_RDWR);
 110         if(ptm == -1)
 111                 if(openpty(&ptm, &pts, NULL, NULL, NULL) == -1)
 112                         eprintn("error, cannot open pty");
 113 #endif
 114 #if defined(_XOPEN_SOURCE)
 115         if(ptm != -1) {
 116                 if(grantpt(ptm) == -1)
 117                         eprintn("error, cannot grant access to pty");
 118                 if(unlockpt(ptm) == -1)
 119                         eprintn("error, cannot unlock pty");
 120                 ptsdev = ptsname(ptm);
 121                 if(!ptsdev)
 122                         eprintn("error, slave pty name undefined");
 123                 pts = open(ptsdev, O_RDWR);
 124                 if(pts == -1)
 125                         eprintn("error, cannot open slave pty");
 126         }
 127         else
 128                 eprintn("error, cannot open pty");
 129 #endif
 130 }
 131
 132 void
 133 movea(int x, int y) {
 134         x = MAX(x, cols);
 135         y = MAX(y, lines);
 136         cx = x;
 137         cy = y;
 138         cmd("s %d,%d", x, y);
 139 }
 140
 141 void
 142 mover(int x, int y) {
 143         movea(cx + x, cy + y);
 144 }
 145
 146 void
 147 parseesc(void) {
 148         int i, j;
 149         int arg[16];
 150
 151         memset(arg, 0, LENGTH(arg));
 152         c = getc(fptm);
 153         switch(c) {
 154         case '[':
 155                 c = getc(fptm);
 156                 for(j = 0; j < LENGTH(arg);) {
 157                         if(isdigit(c)) {
 158                                 digit = 1;
 159                                 arg[j] *= 10;
 160                                 arg[j] += c - '0';
 161                         }
 162                         else if(c == '?')
 163                                 qmark = 1;
 164                         else if(c == ';') {
 165                                 if(!digit)
 166                                         eprint("syntax error\n");
 167                                 digit = 0;
 168                                 j++;
 169                         }
 170                         else {
 171                                 if(digit) {
 172                                         digit = 0;
 173                                         j++;
 174                                 }
 175                                 break;
 176                         }
 177                         c = getc(fptm);
 178                 }
 179                 switch(c) {
 180                 case '@':
 181                         break;
 182                 case 'A':
 183                         mover(0, j ? arg[0] : 1);
 184                         break;
 185                 case 'B':
 186                         mover(0, j ? -arg[0] : -1);
 187                         break;
 188                 case 'C':
 189                         mover(j ? arg[0] : 1, 0);
 190                         break;
 191                 case 'D':
 192                         mover(j ? -arg[0] : -1, 0);
 193                         break;
 194                 case 'E':
 195                         /* movel(j ? arg[0] : 1); */
 196                         break;
 197                 case 'F':
 198                         /* movel(j ? -arg[0] : -1); */
 199                         break;
 200                 case '`':
 201                 case 'G':
 202                         movea(j ? arg[0] : 1, cy);
 203                         break;
 204                 case 'f':
 205                 case 'H':
 206                         movea(arg[1] ? arg[1] : 1, arg[0] ? arg[0] : 1);
 207                 case 'L':
 208                         /* insline(j ? arg[0] : 1); */
 209                         break;
 210                 case 'M':
 211                         /* delline(j ? arg[0] : 1); */
 212                         break;
 213                 case 'P':
 214                         break;
 215                 case 'S':
 216                         scroll(j ? arg[0] : 1);
 217                         break;
 218                 case 'T':
 219                         scroll(j ? -arg[0] : -1);
 220                         break;
 221                 case 'd':
 222                         movea(cx, j ? arg[0] : 1);
 223                         break;
 224                 case 'm':
 225                         for(i = 0; i < j; i++) {
 226                                 if(arg[i] >= 30 && arg[i] <= 37)
 227                                         cmd("#%d", arg[i] - 30);
 228                                 if(arg[i] >= 40 && arg[i] <= 47)
 229                                         cmd("|%d", arg[i] - 40);
 230                                 /* xterm bright colors */
 231                                 if(arg[i] >= 90 && arg[i] <= 97)
 232                                         cmd("#%d", arg[i] - 90);
 233                                 if(arg[i] >= 100 && arg[i] <= 107)
 234                                         cmd("|%d", arg[i] - 100);
 235                                 switch(arg[i]) {
 236                                 case 0:
 237                                 case 22:
 238                                         if(bold)
 239                                                 cmd("b");
 240                                 case 1:
 241                                         if(!bold)
 242                                                 cmd("b");
 243                                         break;
 244                                 }
 245                         }
 246                         break;
 247                 }
 248                 break;
 249         default:
 250                 putchar('\033');
 251                 ungetc(c, fptm);
 252         }
 253 }
 254
 255 void
 256 scroll(int l) {
 257         cmd("s %d, %d", cx, cy + l);
 258 }
 259
 260 void
 261 shell(void) {
 262         static char *shell = NULL;
 263
 264         if(!shell && !(shell = getenv("SHELL")))
 265                 shell = "/bin/sh";
 266         pid = fork();
 267         switch(pid) {
 268         case -1:
 269                 eprint("error, cannot fork\n");
 270         case 0:
 271                 setsid();
 272                 dup2(pts, STDIN_FILENO);
 273                 dup2(pts, STDOUT_FILENO);
 274                 dup2(pts, STDERR_FILENO);
 275                 close(ptm);
 276                 putenv("TERM=vt102");
 277                 execvp(shell, NULL);
 278                 break;
 279         default:
 280                 close(pts);
 281                 signal(SIGCHLD, sigchld);
 282         }
 283 }
 284
 285 void
 286 sigchld(int n) {
 287         int ret;
 288
 289         if(waitpid(pid, &ret, 0) == -1)
 290                 eprintn("error, waiting for child failed");
 291         if(WIFEXITED(ret))
 292                 exit(WEXITSTATUS(ret));
 293         else
 294                 exit(EXIT_SUCCESS);
 295 }
 296
 297 char
 298 unbuffer(void) {
 299         char c;
 300
 301         c = buf.data[buf.s++];
 302         buf.s %= LENGTH(buf.data);
 303         buf.n--;
 304         return c;
 305 }
 306
 307 int
 308 main(int argc, char *argv[]) {
 309         if(argc == 2 && !strcmp("-v", argv[1]))
 310                 eprint("std-"VERSION", © 2008 Matthias-Christian Ott\n");
 311         else if(argc == 1)
 312                 eprint("usage: st [-v]\n");
 313         getpty();
 314         shell();
 315         fptm = fdopen(ptm, "r+");
 316         if(!fptm)
 317                 eprintn("cannot open slave pty");
 318         for(;;) {
 319                 c = getc(fptm);
 320                 switch(c) {
 321                 case '\033':
 322                         parseesc();
 323                         break;
 324                 default:
 325                         putchar(c);
 326                 }
 327         }
 328         return 0;
 329 }