vde-2/src/dpipe.c

   1 /* Copyright 2003 Renzo Davoli
   2  * Licensed under the GPL
   3  */
   4
   5 #include <stdio.h>
   6 #include <unistd.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <sys/types.h>
  10 #include <signal.h>
  11 #include <fcntl.h>
  12
  13 #include <config.h>
  14 #include <vde.h>
  15 #include <vdecommon.h>
  16
  17 #if 0
  18 #define execvp(X,Y) \
  19         ({ char **y; \
  20          fprintf(stderr,"execvp \"%s\" -",(X)); \
  21          for (y=(Y); *y != NULL; y++) \
  22          fprintf(stderr,"\"%s\"",*y); \
  23          fprintf(stderr,"\n"); \
  24          sleep (10); \
  25          })
  26 #endif
  27
  28 static char *progname;
  29
  30 int splitindex(int argc, char *argv[], int *dirchar)
  31 {
  32         register int i;
  33
  34         for (i=0; i<argc; i++) {
  35                 if (*dirchar == argv[i][0] && argv[i][1] == '=' ) {
  36                         (argv[i])++;*dirchar=0;
  37                 }
  38                 if (argv[i][0] == '=') {
  39                         if (argv[i][1] == '}' || argv[i][1] == '{')
  40                                 *dirchar=argv[i][1];
  41                         break;
  42                 }
  43         }
  44         return i;
  45 }
  46
  47 void usage()
  48 {
  49         fprintf(stderr,"Usage:\n\t%s cmd1 [arg1...] = cmd2 [arg2...]\n\n",progname);
  50         kill(getpgrp(),SIGTERM);
  51         exit (-1);
  52 }
  53
  54 static int alternate_stdin;
  55 static int alternate_stdout;
  56 static void alternate_fd()
  57 {
  58         char numstr[10];
  59         alternate_stdin=open("/dev/null",O_RDONLY);
  60         alternate_stdout=open("/dev/null",O_RDONLY);
  61         close(alternate_stdin);
  62         close(alternate_stdout);
  63         snprintf(numstr,10,"%d",alternate_stdin);
  64         setenv("ALTERNATE_STDIN",numstr,1);
  65         snprintf(numstr,10,"%d",alternate_stdout);
  66         setenv("ALTERNATE_STDOUT",numstr,1);
  67 }
  68
  69 int recmain(int argc, char *argv[],int olddirchar)
  70 {
  71         int split;
  72         int newdirchar=olddirchar;
  73
  74         split=splitindex(argc,argv,&newdirchar);
  75         if (split >= argc) {
  76                 if (newdirchar != 0)
  77                         usage();
  78                 execvp(argv[0],argv);
  79         }
  80         else {
  81                 char **argv1,**argv2;
  82                 int p1[2],p2[2];
  83
  84                 if (argc < 3 || split == 0 || split == argc-1)
  85                         usage();
  86
  87                 pipe(p1);
  88                 if (olddirchar == 0) pipe(p2);
  89                 argv[split]=NULL;
  90                 argv1=argv;
  91                 argv2=argv+(split+1);
  92
  93                 if (fork()) {
  94                         switch (olddirchar) {
  95                                 case 0:
  96                                         close(p1[1]); close(p2[0]);
  97                                         if (p1[0] != alternate_stdin){
  98                                                 dup2(p1[0],alternate_stdin);
  99                                                 close(p1[0]);
 100                                         }
 101                                         if (p1[0] != alternate_stdout){
 102                                                 dup2(p2[1],alternate_stdout);
 103                                                 close(p2[1]);
 104                                         }
 105                                         break;
 106                                 case '}':
 107                                         close(p1[0]);
 108                                         dup2(p1[1],STDOUT_FILENO);
 109                                         close(p1[1]);
 110                                         break;
 111                                 case '{':
 112                                         close(p1[1]);
 113                                         dup2(p1[0],STDIN_FILENO);
 114                                         close(p1[0]);
 115                                         break;
 116                                 default:
 117                                         fprintf(stderr,"CHECA\n");
 118                         }
 119                         execvp(argv1[0],argv1);
 120                 } else {
 121                         switch (olddirchar) {
 122                                 case 0:
 123                                         close(p2[1]); close(p1[0]);
 124                                         dup2(p2[0],STDIN_FILENO);
 125                                         dup2(p1[1],STDOUT_FILENO);
 126                                         close(p2[0]); close(p1[1]);
 127                                         break;
 128                                 case '}':
 129                                         close(p1[1]);
 130                                         dup2(p1[0],STDIN_FILENO);
 131                                         close(p1[0]);
 132                                         break;
 133                                 case '{':
 134                                         close(p1[0]);
 135                                         dup2(p1[1],STDOUT_FILENO);
 136                                         close(p1[1]);
 137                                         break;
 138                                 default:
 139                                         fprintf(stderr,"CHECA\n");
 140                         }
 141                         recmain(argc-split-1,argv2,newdirchar);
 142                 }
 143         }
 144         return 0;
 145 }
 146
 147 int main(int argc, char *argv[])
 148 {
 149
 150         int split;
 151         char **argv1,**argv2;
 152         int p1[2],p2[2];
 153         int dirchar=0;
 154
 155         progname=argv[0];
 156         argv++;
 157         argc--;
 158
 159         alternate_fd();
 160         split=splitindex(argc,argv,&dirchar);
 161
 162         if (argc < 3 || split == 0 || split >= argc-1)
 163                 usage();
 164
 165         pipe(p1);
 166         pipe(p2);
 167         argv[split]=NULL;
 168         argv1=argv;
 169         argv2=argv+(split+1);
 170
 171         if (fork()) {
 172                 close(p1[1]); close(p2[0]);
 173                 dup2(p1[0],STDIN_FILENO);
 174                 dup2(p2[1],STDOUT_FILENO);
 175                 close(p1[0]); close(p2[1]);
 176                 execvp(argv1[0],argv1);
 177         } else {
 178                 close(p2[1]); close(p1[0]);
 179                 dup2(p2[0],STDIN_FILENO);
 180                 dup2(p1[1],STDOUT_FILENO);
 181                 close(p1[1]); close(p2[0]);
 182                 recmain(argc-split-1,argv2,dirchar);
 183         }
 184         return (0);
 185 }