cinelerra/pipe.C

   1 #include <fcntl.h>
   2 #include <string.h>
   3 #include <errno.h>
   4 #include <signal.h>
   5
   6 #include "bchash.h"
   7 #include "file.h"
   8 #include "guicast.h"
   9 #include "interlacemodes.h"
  10 #include "pipe.h"
  11
  12 extern "C"
  13 {
  14         int pipe_sigpipe_received;
  15
  16         void pipe_handle_sigpipe(int signum)
  17         {
  18                 printf("Received sigpipe\n");
  19                 pipe_sigpipe_received++;
  20         }
  21 }
  22
  23 Pipe::Pipe(char *command, char *sub_str, char sub_char)
  24 {
  25         this->command = command;
  26         this->sub_str = sub_str;
  27         this->sub_char = sub_char;
  28
  29         complete[0] = '\0';
  30         file = NULL;
  31         fd = -1;
  32
  33         // FUTURE: could probably set to SIG_IGN once things work
  34         signal(SIGPIPE, pipe_handle_sigpipe);
  35 }
  36
  37 Pipe::~Pipe()
  38 {
  39         close();
  40 }
  41
  42 int Pipe::substitute()
  43 {
  44         if (command == NULL)
  45         {
  46                 strcpy(complete, "");
  47                 return 0;
  48         }
  49
  50         if (sub_str == NULL || sub_char == '\0')
  51         {
  52                 strcpy(complete, command);
  53                 return 0;
  54         }
  55
  56         int count = 0;
  57         char *c = command;
  58         char *f = complete;
  59         while (*c)
  60         {
  61                 // directly copy anything substitution char
  62                 if (*c != sub_char)
  63                 {
  64                         *f++ = *c++;
  65                         continue;
  66                 }
  67
  68                 // move over the substitution character
  69                 c++;
  70
  71                 // two substitution characters in a row is literal
  72                 if (*c == sub_char) {
  73                         *f++ = *c++;
  74                         continue;
  75                 }
  76
  77                 // insert the file string at the substitution point
  78                 if (f + strlen(sub_str) - complete > sizeof(complete))
  79                 {
  80                         printf("Pipe::substitute(): max length exceeded\n");
  81                         return -1;
  82                 }
  83                 strcpy(f, sub_str);
  84                 f += strlen(sub_str);
  85                 count++;
  86         }
  87
  88         return count;
  89 }
  90
  91
  92
  93 int Pipe::open(char *mode)
  94 {
  95         if (file) close();
  96
  97         if (mode == NULL)
  98         {
  99                 printf("Pipe::open(): no mode given\n");
 100                 return 1;
 101         }
 102
 103         if (substitute() < 0)
 104                 return 1;
 105
 106         if (complete == NULL || strlen(complete) == 0)
 107         {
 108                 printf("Pipe::open(): no pipe to open\n");
 109                 return 1;
 110         }
 111
 112         printf("trying popen(%s)\n", complete);
 113         file = popen(complete, mode);
 114         if (file != NULL)
 115         {
 116                 fd = fileno(file);
 117                 return 0;
 118         }
 119
 120         // NOTE: popen() fails only if fork/exec fails
 121         //       there is no immediate way to see if command failed
 122         //       As such, one must expect to raise SIGPIPE on failure
 123         printf("Pipe::open(%s,%s) failed: %s\n",
 124                complete, mode, strerror(errno));
 125         return 1;
 126 }
 127
 128 int Pipe::open_read()
 129 {
 130         return open("r");
 131 }
 132
 133 int Pipe::open_write()
 134 {
 135         return open("w");
 136 }
 137
 138 void Pipe::close()
 139 {
 140         pclose(file);
 141         file = 0;
 142         fd = -1;
 143 }