Advanced Programming in the UNIX® Environment

ptg10805159

Appendix C Chapter 5 Solutions 915

ms->vsize = size;

}

fp = funopen(ms, mstream_read, mstream_write,

mstream_seek, mstream_close);

if (fp == NULL) {

if (ms->flags & MS_MYBUF)

free(ms->buf);

free(ms);

}

return(fp);

}

static int

type_to_flags(const char *__restrict type)

{

const char *cp;

int flags = 0;

for (cp = type; *cp != 0; cp++) {

switch (*cp) {

case ’r’:

if (flags != 0)

return(0); /* error */

flags |= MS_READ;

break;

case ’w’:

if (flags != 0)

return(0); /* error */

flags |= MS_WRITE|MS_TRUNCATE;

break;

case ’a’:

if (flags != 0)

return(0); /* error */

flags |= MS_APPEND;

break;

case ’+’:

if (flags == 0)

return(0); /* error */

flags |= MS_READ|MS_WRITE;

break;

case ’b’:

if (flags == 0)

return(0); /* error */

break;

default:

return(0); /* error */

}

}