Function pipe_read_line

src/common/exec.c:362–393

* Execute a command in a pipe and read the first line from it. */

 * Execute a command in a pipe and read the first line from it.
 */
char *
pipe_read_line(char *cmd, char *line, int maxsize)
{
	FILE	   *pgver;

	/* flush output buffers in case popen does not... */
	fflush(stdout);
	fflush(stderr);

	errno = 0;
	if ((pgver = popen(cmd, "r")) == NULL)
	{
		perror("popen failure");
		return NULL;
	}

	errno = 0;
	if (fgets(line, maxsize, pgver) == NULL)
	{
		if (feof(pgver))
			fprintf(stderr, "no data was returned by command \"%s\"\n", cmd);
		else
			perror("fgets failure");
		pclose(pgver);			/* no error checking */
		return NULL;
	}

	if (pclose_check(pgver))
		return NULL;

	return line;
}


/*