lib/ttyutils.c

   1 /*
   2  * No copyright is claimed.  This code is in the public domain; do with
   3  * it what you wish.
   4  *
   5  * Written by Karel Zak <kzak@redhat.com>
   6  */
   7 #include <ctype.h>
   8 #include <unistd.h>
   9
  10 #ifdef HAVE_GETTTYNAM
  11 # include <ttyent.h>
  12 #endif
  13
  14 #include "c.h"
  15 #include "ttyutils.h"
  16
  17 #ifdef __linux__
  18 #  ifndef DEFAULT_VCTERM
  19 #    define DEFAULT_VCTERM "linux"
  20 #  endif
  21 #  if defined (__s390__) || defined (__s390x__)
  22 #    define DEFAULT_TTYS0  "dumb"
  23 #    define DEFAULT_TTY32  "ibm327x"
  24 #    define DEFAULT_TTYS1  "vt220"
  25 #  endif
  26 #  ifndef DEFAULT_STERM
  27 #    define DEFAULT_STERM  "vt102"
  28 #  endif
  29 #elif defined(__GNU__)
  30 #  ifndef DEFAULT_VCTERM
  31 #    define DEFAULT_VCTERM "hurd"
  32 #  endif
  33 #  ifndef DEFAULT_STERM
  34 #    define DEFAULT_STERM  "vt102"
  35 #  endif
  36 #else
  37 #  ifndef DEFAULT_VCTERM
  38 #    define DEFAULT_VCTERM "vt100"
  39 #  endif
  40 #  ifndef DEFAULT_STERM
  41 #    define DEFAULT_STERM  "vt100"
  42 #  endif
  43 #endif
  44
  45 static int get_env_int(const char *name)
  46 {
  47         const char *cp = getenv(name);
  48
  49         if (cp) {
  50                 char *end = NULL;
  51                 long x;
  52
  53                 errno = 0;
  54                 x = strtol(cp, &end, 10);
  55
  56                 if (errno == 0 && end && *end == '\0' && end > cp &&
  57                     x > 0 && x <= INT_MAX)
  58                         return x;
  59         }
  60
  61         return -1;
  62 }
  63
  64 int get_terminal_dimension(int *cols, int *lines)
  65 {
  66         int c = 0, l = 0;
  67
  68 #if defined(TIOCGWINSZ)
  69         struct winsize  w_win;
  70         if (ioctl (STDOUT_FILENO, TIOCGWINSZ, &w_win) == 0) {
  71                 c = w_win.ws_col;
  72                 l = w_win.ws_row;
  73         }
  74 #elif defined(TIOCGSIZE)
  75         struct ttysize  t_win;
  76         if (ioctl (STDOUT_FILENO, TIOCGSIZE, &t_win) == 0) {
  77                 c = t_win.ts_cols;
  78                 l = t_win.ts_lines;
  79         }
  80 #endif
  81         if (cols) {
  82                 if (c <= 0)
  83                         c = get_env_int("COLUMNS");
  84                 *cols = c;
  85         }
  86         if (lines) {
  87                 if (l <= 0)
  88                         l = get_env_int("LINES");
  89                 *lines = l;
  90         }
  91         return 0;
  92 }
  93
  94 int get_terminal_width(int default_width)
  95 {
  96         int width = 0;
  97
  98         get_terminal_dimension(&width, NULL);
  99
 100         return width > 0 ? width : default_width;
 101 }
 102
 103 int get_terminal_stdfd(void)
 104 {
 105         if (isatty(STDIN_FILENO))
 106                 return STDIN_FILENO;
 107         if (isatty(STDOUT_FILENO))
 108                 return STDOUT_FILENO;
 109         if (isatty(STDERR_FILENO))
 110                 return STDERR_FILENO;
 111
 112         return -EINVAL;
 113 }
 114
 115 int get_terminal_name(const char **path,
 116                       const char **name,
 117                       const char **number)
 118 {
 119         const char *tty;
 120         const char *p;
 121         int fd;
 122
 123
 124         if (name)
 125                 *name = NULL;
 126         if (path)
 127                 *path = NULL;
 128         if (number)
 129                 *number = NULL;
 130
 131         fd = get_terminal_stdfd();
 132         if (fd < 0)
 133                 return fd;      /* error */
 134
 135         tty = ttyname(fd);
 136         if (!tty)
 137                 return -1;
 138
 139         if (path)
 140                 *path = tty;
 141         if (name || number)
 142                 tty = strncmp(tty, "/dev/", 5) == 0 ? tty + 5 : tty;
 143         if (name)
 144                 *name = tty;
 145         if (number) {
 146                 for (p = tty; p && *p; p++) {
 147                         if (isdigit(*p)) {
 148                                 *number = p;
 149                                 break;
 150                         }
 151                 }
 152         }
 153         return 0;
 154 }
 155
 156 int get_terminal_type(const char **type)
 157 {
 158         *type = getenv("TERM");
 159         if (*type)
 160                 return -EINVAL;
 161         return 0;
 162 }
 163
 164 char *get_terminal_default_type(const char *ttyname, int is_serial)
 165 {
 166         if (ttyname) {
 167 #ifdef HAVE_GETTTYNAM
 168                 struct ttyent *ent = getttynam(ttyname);
 169
 170                 if (ent && ent->ty_type)
 171                         return strdup(ent->ty_type);
 172 #endif
 173
 174 #if defined (__s390__) || defined (__s390x__)
 175                 /*
 176                  * Special terminal on first serial line on a S/390(x) which
 177                  * is due legacy reasons a block terminal of type 3270 or
 178                  * higher.  Whereas the second serial line on a S/390(x) is
 179                  * a real character terminal which is compatible with VT220.
 180                  */
 181                 if (strcmp(ttyname, "ttyS0") == 0)              /* linux/drivers/s390/char/con3215.c */
 182                         return strdup(DEFAULT_TTYS0);
 183                 else if (strncmp(ttyname, "3270/tty", 8) == 0)  /* linux/drivers/s390/char/con3270.c */
 184                         return strdup(DEFAULT_TTY32);
 185                 else if (strcmp(ttyname, "ttyS1") == 0)         /* linux/drivers/s390/char/sclp_vt220.c */
 186                         return strdup(DEFAULT_TTYS1);
 187 #endif
 188         }
 189
 190         return strdup(is_serial ? DEFAULT_STERM : DEFAULT_VCTERM);
 191 }
 192
 193 #ifdef TEST_PROGRAM_TTYUTILS
 194 # include <stdlib.h>
 195 int main(void)
 196 {
 197         const char *path, *name, *num;
 198         int c, l;
 199
 200         if (get_terminal_name(&path, &name, &num) == 0) {
 201                 char *term;
 202
 203                 fprintf(stderr, "tty path:      %s\n", path);
 204                 fprintf(stderr, "tty name:      %s\n", name);
 205                 fprintf(stderr, "tty number:    %s\n", num);
 206
 207                 fprintf(stderr, "tty term:      %s\n", getenv("TERM"));
 208
 209                 term = get_terminal_default_type(name, 0);
 210                 fprintf(stderr, "tty dflt term: %s\n", term);
 211                 free(term);
 212         }
 213         get_terminal_dimension(&c, &l);
 214         fprintf(stderr,         "tty cols:      %d\n", c);
 215         fprintf(stderr,         "tty lines:     %d\n", l);
 216
 217
 218         return EXIT_SUCCESS;
 219 }
 220 #endif /* TEST_PROGRAM_TTYUTILS */