contrib/less/lsystem.c

   1 /*
   2  * Copyright (C) 1984-2019  Mark Nudelman
   3  *
   4  * You may distribute under the terms of either the GNU General Public
   5  * License or the Less License, as specified in the README file.
   6  *
   7  * For more information, see the README file.
   8  */
   9
  10
  11 /*
  12  * Routines to execute other programs.
  13  * Necessarily very OS dependent.
  14  */
  15
  16 #include "less.h"
  17 #include <signal.h>
  18 #include "position.h"
  19
  20 #if MSDOS_COMPILER
  21 #include <dos.h>
  22 #if MSDOS_COMPILER==WIN32C && defined(MINGW)
  23 #include <direct.h>
  24 #define setdisk(n) _chdrive((n)+1)
  25 #else
  26 #ifdef _MSC_VER
  27 #include <direct.h>
  28 #define setdisk(n) _chdrive((n)+1)
  29 #else
  30 #include <dir.h>
  31 #endif
  32 #endif
  33 #endif
  34
  35 extern int screen_trashed;
  36 extern IFILE curr_ifile;
  37
  38
  39 #if HAVE_SYSTEM
  40
  41 /*
  42  * Pass the specified command to a shell to be executed.
  43  * Like plain "system()", but handles resetting terminal modes, etc.
  44  */
  45         public void
  46 lsystem(cmd, donemsg)
  47         char *cmd;
  48         char *donemsg;
  49 {
  50         int inp;
  51 #if HAVE_SHELL
  52         char *shell;
  53         char *p;
  54 #endif
  55         IFILE save_ifile;
  56 #if MSDOS_COMPILER && MSDOS_COMPILER!=WIN32C
  57         char cwd[FILENAME_MAX+1];
  58 #endif
  59
  60         /*
  61          * Print the command which is to be executed,
  62          * unless the command starts with a "-".
  63          */
  64         if (cmd[0] == '-')
  65                 cmd++;
  66         else
  67         {
  68                 clear_bot();
  69                 putstr("!");
  70                 putstr(cmd);
  71                 putstr("\n");
  72         }
  73
  74 #if MSDOS_COMPILER
  75 #if MSDOS_COMPILER==WIN32C
  76         if (*cmd == '\0')
  77                 cmd = getenv("COMSPEC");
  78 #else
  79         /*
  80          * Working directory is global on MSDOS.
  81          * The child might change the working directory, so we
  82          * must save and restore CWD across calls to "system",
  83          * or else we won't find our file when we return and
  84          * try to "reedit_ifile" it.
  85          */
  86         getcwd(cwd, FILENAME_MAX);
  87 #endif
  88 #endif
  89
  90         /*
  91          * Close the current input file.
  92          */
  93         save_ifile = save_curr_ifile();
  94         (void) edit_ifile(NULL_IFILE);
  95
  96         /*
  97          * De-initialize the terminal and take out of raw mode.
  98          */
  99         deinit();
 100         flush();        /* Make sure the deinit chars get out */
 101         raw_mode(0);
 102 #if MSDOS_COMPILER==WIN32C
 103         close_getchr();
 104 #endif
 105
 106         /*
 107          * Restore signals to their defaults.
 108          */
 109         init_signals(0);
 110
 111 #if HAVE_DUP
 112         /*
 113          * Force standard input to be the user's terminal
 114          * (the normal standard input), even if less's standard input
 115          * is coming from a pipe.
 116          */
 117         inp = dup(0);
 118         close(0);
 119 #if OS2
 120         /* The __open() system call translates "/dev/tty" to "con". */
 121         if (__open("/dev/tty", OPEN_READ) < 0)
 122 #else
 123         if (open("/dev/tty", OPEN_READ) < 0)
 124 #endif
 125                 dup(inp);
 126 #endif
 127
 128         /*
 129          * Pass the command to the system to be executed.
 130          * If we have a SHELL environment variable, use
 131          * <$SHELL -c "command"> instead of just <command>.
 132          * If the command is empty, just invoke a shell.
 133          */
 134 #if HAVE_SHELL
 135         p = NULL;
 136         if ((shell = lgetenv("SHELL")) != NULL && *shell != '\0')
 137         {
 138                 if (*cmd == '\0')
 139                         p = save(shell);
 140                 else
 141                 {
 142                         char *esccmd = shell_quote(cmd);
 143                         if (esccmd != NULL)
 144                         {
 145                                 int len = (int) (strlen(shell) + strlen(esccmd) + 5);
 146                                 p = (char *) ecalloc(len, sizeof(char));
 147                                 SNPRINTF3(p, len, "%s %s %s", shell, shell_coption(), esccmd);
 148                                 free(esccmd);
 149                         }
 150                 }
 151         }
 152         if (p == NULL)
 153         {
 154                 if (*cmd == '\0')
 155                         p = save("sh");
 156                 else
 157                         p = save(cmd);
 158         }
 159         system(p);
 160         free(p);
 161 #else
 162 #if MSDOS_COMPILER==DJGPPC
 163         /*
 164          * Make stdin of the child be in cooked mode.
 165          */
 166         setmode(0, O_TEXT);
 167         /*
 168          * We don't need to catch signals of the child (it
 169          * also makes trouble with some DPMI servers).
 170          */
 171         __djgpp_exception_toggle();
 172         system(cmd);
 173         __djgpp_exception_toggle();
 174 #else
 175         system(cmd);
 176 #endif
 177 #endif
 178
 179 #if HAVE_DUP
 180         /*
 181          * Restore standard input, reset signals, raw mode, etc.
 182          */
 183         close(0);
 184         dup(inp);
 185         close(inp);
 186 #endif
 187
 188 #if MSDOS_COMPILER==WIN32C
 189         open_getchr();
 190 #endif
 191         init_signals(1);
 192         raw_mode(1);
 193         if (donemsg != NULL)
 194         {
 195                 putstr(donemsg);
 196                 putstr("  (press RETURN)");
 197                 get_return();
 198                 putchr('\n');
 199                 flush();
 200         }
 201         init();
 202         screen_trashed = 1;
 203
 204 #if MSDOS_COMPILER && MSDOS_COMPILER!=WIN32C
 205         /*
 206          * Restore the previous directory (possibly
 207          * changed by the child program we just ran).
 208          */
 209         chdir(cwd);
 210 #if MSDOS_COMPILER != DJGPPC
 211         /*
 212          * Some versions of chdir() don't change to the drive
 213          * which is part of CWD.  (DJGPP does this in chdir.)
 214          */
 215         if (cwd[1] == ':')
 216         {
 217                 if (cwd[0] >= 'a' && cwd[0] <= 'z')
 218                         setdisk(cwd[0] - 'a');
 219                 else if (cwd[0] >= 'A' && cwd[0] <= 'Z')
 220                         setdisk(cwd[0] - 'A');
 221         }
 222 #endif
 223 #endif
 224
 225         /*
 226          * Reopen the current input file.
 227          */
 228         reedit_ifile(save_ifile);
 229
 230 #if defined(SIGWINCH) || defined(SIGWIND)
 231         /*
 232          * Since we were ignoring window change signals while we executed
 233          * the system command, we must assume the window changed.
 234          * Warning: this leaves a signal pending (in "sigs"),
 235          * so psignals() should be called soon after lsystem().
 236          */
 237         winch(0);
 238 #endif
 239 }
 240
 241 #endif
 242
 243 #if PIPEC
 244
 245 /*
 246  * Pipe a section of the input file into the given shell command.
 247  * The section to be piped is the section "between" the current
 248  * position and the position marked by the given letter.
 249  *
 250  * If the mark is after the current screen, the section between
 251  * the top line displayed and the mark is piped.
 252  * If the mark is before the current screen, the section between
 253  * the mark and the bottom line displayed is piped.
 254  * If the mark is on the current screen, or if the mark is ".",
 255  * the whole current screen is piped.
 256  */
 257         public int
 258 pipe_mark(c, cmd)
 259         int c;
 260         char *cmd;
 261 {
 262         POSITION mpos, tpos, bpos;
 263
 264         /*
 265          * mpos = the marked position.
 266          * tpos = top of screen.
 267          * bpos = bottom of screen.
 268          */
 269         mpos = markpos(c);
 270         if (mpos == NULL_POSITION)
 271                 return (-1);
 272         tpos = position(TOP);
 273         if (tpos == NULL_POSITION)
 274                 tpos = ch_zero();
 275         bpos = position(BOTTOM);
 276
 277         if (c == '.')
 278                 return (pipe_data(cmd, tpos, bpos));
 279         else if (mpos <= tpos)
 280                 return (pipe_data(cmd, mpos, bpos));
 281         else if (bpos == NULL_POSITION)
 282                 return (pipe_data(cmd, tpos, bpos));
 283         else
 284                 return (pipe_data(cmd, tpos, mpos));
 285 }
 286
 287 /*
 288  * Create a pipe to the given shell command.
 289  * Feed it the file contents between the positions spos and epos.
 290  */
 291         public int
 292 pipe_data(cmd, spos, epos)
 293         char *cmd;
 294         POSITION spos;
 295         POSITION epos;
 296 {
 297         FILE *f;
 298         int c;
 299
 300         /*
 301          * This is structured much like lsystem().
 302          * Since we're running a shell program, we must be careful
 303          * to perform the necessary deinitialization before running
 304          * the command, and reinitialization after it.
 305          */
 306         if (ch_seek(spos) != 0)
 307         {
 308                 error("Cannot seek to start position", NULL_PARG);
 309                 return (-1);
 310         }
 311
 312         if ((f = popen(cmd, "w")) == NULL)
 313         {
 314                 error("Cannot create pipe", NULL_PARG);
 315                 return (-1);
 316         }
 317         clear_bot();
 318         putstr("!");
 319         putstr(cmd);
 320         putstr("\n");
 321
 322         deinit();
 323         flush();
 324         raw_mode(0);
 325         init_signals(0);
 326 #if MSDOS_COMPILER==WIN32C
 327         close_getchr();
 328 #endif
 329 #ifdef SIGPIPE
 330         LSIGNAL(SIGPIPE, SIG_IGN);
 331 #endif
 332
 333         c = EOI;
 334         while (epos == NULL_POSITION || spos++ <= epos)
 335         {
 336                 /*
 337                  * Read a character from the file and give it to the pipe.
 338                  */
 339                 c = ch_forw_get();
 340                 if (c == EOI)
 341                         break;
 342                 if (putc(c, f) == EOF)
 343                         break;
 344         }
 345
 346         /*
 347          * Finish up the last line.
 348          */
 349         while (c != '\n' && c != EOI )
 350         {
 351                 c = ch_forw_get();
 352                 if (c == EOI)
 353                         break;
 354                 if (putc(c, f) == EOF)
 355                         break;
 356         }
 357
 358         pclose(f);
 359
 360 #ifdef SIGPIPE
 361         LSIGNAL(SIGPIPE, SIG_DFL);
 362 #endif
 363 #if MSDOS_COMPILER==WIN32C
 364         open_getchr();
 365 #endif
 366         init_signals(1);
 367         raw_mode(1);
 368         init();
 369         screen_trashed = 1;
 370 #if defined(SIGWINCH) || defined(SIGWIND)
 371         /* {{ Probably don't need this here. }} */
 372         winch(0);
 373 #endif
 374         return (0);
 375 }
 376
 377 #endif