Improve reporting of error situations in find_other_exec().

This function suppressed any stderr output from the called program, which
is unnecessary in the normal case and unhelpful in error cases.  It also
gave a rather opaque message along the lines of "fgets failure: Success"
in case the called program failed to return anything on stdout.  Since
we've seen multiple reports of people not understanding what's wrong when
pg_ctl reports this, improve the message.

Back-patch to all active branches.
This commit is contained in:
Tom Lane 2012-07-27 19:31:13 -04:00
parent c9a2532c83
commit 9ae8ebe0b2

View File

@ -322,7 +322,7 @@ find_other_exec(const char *argv0, const char *target,
if (validate_exec(retpath) != 0)
return -1;
snprintf(cmd, sizeof(cmd), "\"%s\" -V 2>%s", retpath, DEVNULL);
snprintf(cmd, sizeof(cmd), "\"%s\" -V", retpath);
if (!pipe_read_line(cmd, line, sizeof(line)))
return -1;
@ -352,11 +352,19 @@ pipe_read_line(char *cmd, char *line, int maxsize)
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;