contrib/less/lsystem.c

   1 /*
   2  * Copyright (C) 1984-2007  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 about less, or for information on how to
   8  * contact the author, see the README file.
   9  */
  10
  11
  12 /*
  13  * Routines to execute other programs.
  14  * Necessarily very OS dependent.
  15  */
  16
  17 #include "less.h"
  18 #include <signal.h>
  19 #include "position.h"
  20
  21 #if MSDOS_COMPILER
  22 #include <dos.h>
  23 #ifdef _MSC_VER
  24 #include <direct.h>
  25 #define setdisk(n) _chdrive((n)+1)
  26 #else
  27 #include <dir.h>
  28 #endif
  29 #endif
  30
  31 extern int screen_trashed;
  32 extern IFILE curr_ifile;
  33
  34
  35 #if HAVE_SYSTEM
  36
  37 /*
  38  * Pass the specified command to a shell to be executed.
  39  * Like plain "system()", but handles resetting terminal modes, etc.
  40  */
  41         public void
  42 lsystem(cmd, donemsg)
  43         char *cmd;
  44         char *donemsg;
  45 {
  46         register int inp;
  47 #if HAVE_SHELL
  48         register char *shell;
  49         register char *p;
  50 #endif
  51         IFILE save_ifile;
  52 #if MSDOS_COMPILER
  53         char cwd[FILENAME_MAX+1];
  54 #endif
  55
  56         /*
  57          * Print the command which is to be executed,
  58          * unless the command starts with a "-".
  59          */
  60         if (cmd[0] == '-')
  61                 cmd++;
  62         else
  63         {
  64                 clear_bot();
  65                 putstr("!");
  66                 putstr(cmd);
  67                 putstr("\n");
  68         }
  69
  70 #if MSDOS_COMPILER
  71         /*
  72          * Working directory is global on MSDOS.
  73          * The child might change the working directory, so we
  74          * must save and restore CWD across calls to "system",
  75          * or else we won't find our file when we return and
  76          * try to "reedit_ifile" it.
  77          */
  78         getcwd(cwd, FILENAME_MAX);
  79 #endif
  80
  81         /*
  82          * Close the current input file.
  83          */
  84         save_ifile = save_curr_ifile();
  85         (void) edit_ifile(NULL_IFILE);
  86
  87         /*
  88          * De-initialize the terminal and take out of raw mode.
  89          */
  90         deinit();
  91         flush();        /* Make sure the deinit chars get out */
  92         raw_mode(0);
  93 #if MSDOS_COMPILER==WIN32C
  94         close_getchr();
  95 #endif
  96
  97         /*
  98          * Restore signals to their defaults.
  99          */
 100         init_signals(0);
 101
 102 #if HAVE_DUP
 103         /*
 104          * Force standard input to be the user's terminal
 105          * (the normal standard input), even if less's standard input
 106          * is coming from a pipe.
 107          */
 108         inp = dup(0);
 109         close(0);
 110 #if OS2
 111         /* The __open() system call translates "/dev/tty" to "con". */
 112         if (__open("/dev/tty", OPEN_READ) < 0)
 113 #else
 114         if (open("/dev/tty", OPEN_READ) < 0)
 115 #endif
 116                 dup(inp);
 117 #endif
 118
 119         /*
 120          * Pass the command to the system to be executed.
 121          * If we have a SHELL environment variable, use
 122          * <$SHELL -c "command"> instead of just <command>.
 123          * If the command is empty, just invoke a shell.
 124          */
 125 #if HAVE_SHELL
 126         p = NULL;
 127         if ((shell = lgetenv("SHELL")) != NULL && *shell != '\0')
 128         {
 129                 if (*cmd == '\0')
 130                         p = save(shell);
 131                 else
 132                 {
 133                         char *esccmd = shell_quote(cmd);
 134                         if (esccmd != NULL)
 135                         {
 136                                 int len = strlen(shell) + strlen(esccmd) + 5;
 137                                 p = (char *) ecalloc(len, sizeof(char));
 138                                 SNPRINTF3(p, len, "%s %s %s", shell, shell_coption(), esccmd);
 139                                 free(esccmd);
 140                         }
 141                 }
 142         }
 143         if (p == NULL)
 144         {
 145                 if (*cmd == '\0')
 146                         p = save("sh");
 147                 else
 148                         p = save(cmd);
 149         }
 150         system(p);
 151         free(p);
 152 #else
 153 #if MSDOS_COMPILER==DJGPPC
 154         /*
 155          * Make stdin of the child be in cooked mode.
 156          */
 157         setmode(0, O_TEXT);
 158         /*
 159          * We don't need to catch signals of the child (it
 160          * also makes trouble with some DPMI servers).
 161          */
 162         __djgpp_exception_toggle();
 163         system(cmd);
 164         __djgpp_exception_toggle();
 165 #else
 166         system(cmd);
 167 #endif
 168 #endif
 169
 170 #if HAVE_DUP
 171         /*
 172          * Restore standard input, reset signals, raw mode, etc.
 173          */
 174         close(0);
 175         dup(inp);
 176         close(inp);
 177 #endif
 178
 179 #if MSDOS_COMPILER==WIN32C
 180         open_getchr();
 181 #endif
 182         init_signals(1);
 183         raw_mode(1);
 184         if (donemsg != NULL)
 185         {
 186                 putstr(donemsg);
 187                 putstr("  (press RETURN)");
 188                 get_return();
 189                 putchr('\n');
 190                 flush();
 191         }
 192         init();
 193         screen_trashed = 1;
 194
 195 #if MSDOS_COMPILER
 196         /*
 197          * Restore the previous directory (possibly
 198          * changed by the child program we just ran).
 199          */
 200         chdir(cwd);
 201 #if MSDOS_COMPILER != DJGPPC
 202         /*
 203          * Some versions of chdir() don't change to the drive
 204          * which is part of CWD.  (DJGPP does this in chdir.)
 205          */
 206         if (cwd[1] == ':')
 207         {
 208                 if (cwd[0] >= 'a' && cwd[0] <= 'z')
 209                         setdisk(cwd[0] - 'a');
 210                 else if (cwd[0] >= 'A' && cwd[0] <= 'Z')
 211                         setdisk(cwd[0] - 'A');
 212         }
 213 #endif
 214 #endif
 215
 216         /*
 217          * Reopen the current input file.
 218          */
 219         reedit_ifile(save_ifile);
 220
 221 #if defined(SIGWINCH) || defined(SIGWIND)
 222         /*
 223          * Since we were ignoring window change signals while we executed
 224          * the system command, we must assume the window changed.
 225          * Warning: this leaves a signal pending (in "sigs"),
 226          * so psignals() should be called soon after lsystem().
 227          */
 228         winch(0);
 229 #endif
 230 }
 231
 232 #endif
 233
 234 #if PIPEC
 235
 236 /*
 237  * Pipe a section of the input file into the given shell command.
 238  * The section to be piped is the section "between" the current
 239  * position and the position marked by the given letter.
 240  *
 241  * If the mark is after the current screen, the section between
 242  * the top line displayed and the mark is piped.
 243  * If the mark is before the current screen, the section between
 244  * the mark and the bottom line displayed is piped.
 245  * If the mark is on the current screen, or if the mark is ".",
 246  * the whole current screen is piped.
 247  */
 248         public int
 249 pipe_mark(c, cmd)
 250         int c;
 251         char *cmd;
 252 {
 253         POSITION mpos, tpos, bpos;
 254
 255         /*
 256          * mpos = the marked position.
 257          * tpos = top of screen.
 258          * bpos = bottom of screen.
 259          */
 260         mpos = markpos(c);
 261         if (mpos == NULL_POSITION)
 262                 return (-1);
 263         tpos = position(TOP);
 264         if (tpos == NULL_POSITION)
 265                 tpos = ch_zero();
 266         bpos = position(BOTTOM);
 267
 268         if (c == '.')
 269                 return (pipe_data(cmd, tpos, bpos));
 270         else if (mpos <= tpos)
 271                 return (pipe_data(cmd, mpos, bpos));
 272         else if (bpos == NULL_POSITION)
 273                 return (pipe_data(cmd, tpos, bpos));
 274         else
 275                 return (pipe_data(cmd, tpos, mpos));
 276 }
 277
 278 /*
 279  * Create a pipe to the given shell command.
 280  * Feed it the file contents between the positions spos and epos.
 281  */
 282         public int
 283 pipe_data(cmd, spos, epos)
 284         char *cmd;
 285         POSITION spos;
 286         POSITION epos;
 287 {
 288         register FILE *f;
 289         register int c;
 290         extern FILE *popen();
 291
 292         /*
 293          * This is structured much like lsystem().
 294          * Since we're running a shell program, we must be careful
 295          * to perform the necessary deinitialization before running
 296          * the command, and reinitialization after it.
 297          */
 298         if (ch_seek(spos) != 0)
 299         {
 300                 error("Cannot seek to start position", NULL_PARG);
 301                 return (-1);
 302         }
 303
 304         if ((f = popen(cmd, "w")) == NULL)
 305         {
 306                 error("Cannot create pipe", NULL_PARG);
 307                 return (-1);
 308         }
 309         clear_bot();
 310         putstr("!");
 311         putstr(cmd);
 312         putstr("\n");
 313
 314         deinit();
 315         flush();
 316         raw_mode(0);
 317         init_signals(0);
 318 #if MSDOS_COMPILER==WIN32C
 319         close_getchr();
 320 #endif
 321 #ifdef SIGPIPE
 322         LSIGNAL(SIGPIPE, SIG_IGN);
 323 #endif
 324
 325         c = EOI;
 326         while (epos == NULL_POSITION || spos++ <= epos)
 327         {
 328                 /*
 329                  * Read a character from the file and give it to the pipe.
 330                  */
 331                 c = ch_forw_get();
 332                 if (c == EOI)
 333                         break;
 334                 if (putc(c, f) == EOF)
 335                         break;
 336         }
 337
 338         /*
 339          * Finish up the last line.
 340          */
 341         while (c != '\n' && c != EOI )
 342         {
 343                 c = ch_forw_get();
 344                 if (c == EOI)
 345                         break;
 346                 if (putc(c, f) == EOF)
 347                         break;
 348         }
 349
 350         pclose(f);
 351
 352 #ifdef SIGPIPE
 353         LSIGNAL(SIGPIPE, SIG_DFL);
 354 #endif
 355 #if MSDOS_COMPILER==WIN32C
 356         open_getchr();
 357 #endif
 358         init_signals(1);
 359         raw_mode(1);
 360         init();
 361         screen_trashed = 1;
 362 #if defined(SIGWINCH) || defined(SIGWIND)
 363         /* {{ Probably don't need this here. }} */
 364         winch(0);
 365 #endif
 366         return (0);
 367 }
 368
 369 #endif