summaryrefslogtreecommitdiff
path: root/recordio.c
blob: a3ee03c2d26bca4dde3d346beb9c773a2dae3777 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#include "sig.h"
#include "buffer.h"
#include "strerr.h"
#include "str.h"
#include "byte.h"
#include "readwrite.h"
#include "exit.h"
#include "fmt.h"
#include "iopause.h"
#include "pathexec.h"

#define FATAL "recordio: fatal: "

char pid[FMT_ULONG];

char recordbuf[512];
buffer ssrecord = BUFFER_INIT(write,2,recordbuf,sizeof recordbuf);

void record(char *buf,int len,char *direction) /* 1 <= len <= 256 */
{
  int i;

  while (len) {
    buffer_puts(&ssrecord,pid);
    buffer_puts(&ssrecord,direction);

    i = byte_chr(buf,len,'\n');
    buffer_put(&ssrecord,buf,i);

    if (i == len) {
      buffer_puts(&ssrecord,"+\n");
      buffer_flush(&ssrecord);
      return;
    }

    buffer_puts(&ssrecord," \n");
    buffer_flush(&ssrecord);
    buf += i + 1;
    len -= i + 1;
  }
}

int leftstatus = 0;
char leftbuf[256];
int leftlen;
int leftpos;

int rightstatus = 0;
char rightbuf[256];
int rightlen;
int rightpos;

void doit(int fdleft,int fdright) /* copy 0 -> fdleft, copy fdright -> 1 */
{
  struct taia stamp;
  struct taia deadline;
  iopause_fd x[4];
  int xlen;
  iopause_fd *io0;
  iopause_fd *ioleft;
  iopause_fd *io1;
  iopause_fd *ioright;
  int r;

  for (;;) {
    xlen = 0;

    io0 = 0;
    if (leftstatus == 0) {
      io0 = &x[xlen++];
      io0->fd = 0;
      io0->events = IOPAUSE_READ;
    }
    ioleft = 0;
    if (leftstatus == 1) {
      ioleft = &x[xlen++];
      ioleft->fd = fdleft;
      ioleft->events = IOPAUSE_WRITE;
    }

    ioright = 0;
    if (rightstatus == 0) {
      ioright = &x[xlen++];
      ioright->fd = fdright;
      ioright->events = IOPAUSE_READ;
    }
    io1 = 0;
    if (rightstatus == 1) {
      io1 = &x[xlen++];
      io1->fd = 1;
      io1->events = IOPAUSE_WRITE;
    }

    taia_now(&stamp);
    taia_uint(&deadline,3600);
    taia_add(&deadline,&stamp,&deadline);
    iopause(x,xlen,&deadline,&stamp);

    if (io0 && io0->revents) {
      r = read(0,leftbuf,sizeof leftbuf);
      if (r <= 0) {
        leftstatus = -1;
        close(fdleft);
        buffer_puts(&ssrecord,pid);
        buffer_puts(&ssrecord," < [EOF]\n");
        buffer_flush(&ssrecord);
      }
      else {
        leftstatus = 1; leftpos = 0; leftlen = r;
        record(leftbuf,r," < ");
      }
    }

    if (ioleft && ioleft->revents) {
      r = write(fdleft,leftbuf + leftpos,leftlen - leftpos);
      if (r == -1) break;
      leftpos += r;
      if (leftpos == leftlen) leftstatus = 0;
    }

    if (ioright && ioright->revents) {
      r = read(fdright,rightbuf,sizeof rightbuf);
      if (r <= 0) {
        buffer_puts(&ssrecord,pid);
        buffer_puts(&ssrecord," > [EOF]\n");
        buffer_flush(&ssrecord);
        break;
      }
      rightstatus = 1; rightpos = 0; rightlen = r;
      record(rightbuf,r," > ");
    }

    if (io1 && io1->revents) {
      r = write(1,rightbuf + rightpos,rightlen - rightpos);
      if (r == -1) break;
      rightpos += r;
      if (rightpos == rightlen) rightstatus = 0;
    }
  }

  _exit(0);
}

main(int argc,char **argv,char **envp)
{
  int piin[2];
  int piout[2];

  pid[fmt_ulong(pid,getpid())] = 0;

  if (argc < 2)
    strerr_die1x(100,"recordio: usage: recordio program [ arg ... ]");

  if (pipe(piin) == -1)
    strerr_die2sys(111,FATAL,"unable to create pipe: ");
  if (pipe(piout) == -1)
    strerr_die2sys(111,FATAL,"unable to create pipe: ");

  switch(fork()) {
    case -1:
      strerr_die2sys(111,FATAL,"unable to fork: ");
    case 0:
      sig_ignore(sig_pipe);
      close(piin[0]);
      close(piout[1]);
      doit(piin[1],piout[0]);
  }

  close(piin[1]);
  close(piout[0]);
  if (fd_move(0,piin[0]) == -1)
    strerr_die2sys(111,FATAL,"unable to move descriptors: ");
  if (fd_move(1,piout[1]) == -1)
    strerr_die2sys(111,FATAL,"unable to move descriptors: ");

  pathexec_run(argv[1],argv + 1,envp);
  strerr_die4sys(111,FATAL,"unable to run ",argv[1],": ");
}