/**
* @brief Main child function
* @details Exits after execution
* @param id Number of the created child (starting with 1)
* @param opts Parameters from command line, PRE: != null
* @param ipipe Input pipe for a child process
* PRE: != null, size = 2 * int
* @param opipe Output pipe for a child process
* PRE: != null, size = 2 * int
*/
void child_main(int id, struct options *opts, int *ipipe,
int *opipe)
{
char buff[SECRET_MAX];
FILE *stream;
/* Open input stream */
stream = fdopen(ipipe[0], "r");
if (stream == NULL)
bail_out(EXIT_FAILURE, "fdopen");
/* Read from input pipe */
if (close(ipipe[1]) == -1)
bail_out(EXIT_FAILURE, "close");
if (quit == 0 && fread(buff, 1, opts->slen,
stream) == -1) {
bail_out(EXIT_FAILURE, "read");
}
if (close(ipipe[0]) == -1)
bail_out(EXIT_FAILURE, "close");
/* Randomly alter string, verbose output */
if (quit == 0 && opts->verbose) {
(void) printf("child%02d: erhalten: %s\n",
id, buff);
}
alter_string(id, buff, opts->slen - 1);
if (quit == 0 && opts->verbose) {
(void) printf("child%02d: weiter : %s\n",
id, buff);
}
/* Handle output */
if (id < opts->num_childs) {
if (close(opipe[0]) == -1)
bail_out(EXIT_FAILURE, "close");
/* Get file descriptor for writing */
stream = fdopen(opipe[1], "w");
if (stream == NULL)
bail_out(EXIT_FAILURE, "fdopen");
if (quit == 0 && fwrite(buff, 1, opts->slen,
stream) == -1) {
bail_out(EXIT_FAILURE, "write");
}
if (fflush(stream))
bail_out(EXIT_FAILURE, "fflush");
if (close(opipe[1]) == -1)
bail_out(EXIT_FAILURE, "close");
} else {
(void) printf("child%02d: Ende : %s\n",
id, buff);
}
/* Return failure on exit */
if (quit == 1)
exit(EXIT_FAILURE);
exit(EXIT_SUCCESS);
}
int main()
{
alter_string ("Hello, world!\n");
};
