diff options
Diffstat (limited to 'src/bin/psql/psql.c')
| -rw-r--r-- | src/bin/psql/psql.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/src/bin/psql/psql.c b/src/bin/psql/psql.c index 1ed9e4561fd..65692bd9a11 100644 --- a/src/bin/psql/psql.c +++ b/src/bin/psql/psql.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/bin/psql/Attic/psql.c,v 1.146 1998/06/16 07:29:38 momjian Exp $ + * $Header: /cvsroot/pgsql/src/bin/psql/Attic/psql.c,v 1.147 1998/07/09 03:28:53 scrappy Exp $ * *------------------------------------------------------------------------- */ @@ -291,27 +291,41 @@ PSQLexec(PsqlSettings *pset, char *query) * If interactive, we enable a SIGINT signal catcher that sends * a cancel request to the backend. * Note that sending the cancel directly from the signal handler - * is safe only because the cancel is sent as an OOB message. - * If it were inline data, then we'd risk inserting it into the - * middle of a normal data message by doing this. - * (It's probably not too cool to write on stderr, for that matter... - * but for debugging purposes we'll risk that.) + * is safe only because PQrequestCancel is carefully written to + * make it so. We have to be very careful what else we do in the + * signal handler. + * Writing on stderr is potentially dangerous, if the signal interrupted + * some stdio operation on stderr. On Unix we can avoid trouble by using + * write() instead; on Windows that's probably not workable, but we can + * at least avoid trusting printf by using the more primitive fputs. */ static PGconn * cancelConn = NULL; /* connection to try cancel on */ static void +safe_write_stderr (const char * s) +{ +#ifdef WIN32 + fputs(s, stderr); +#else + write(fileno(stderr), s, strlen(s)); +#endif +} + +static void handle_sigint (SIGNAL_ARGS) { if (cancelConn == NULL) exit(1); /* accept signal if no connection */ /* Try to send cancel request */ if (PQrequestCancel(cancelConn)) - fprintf(stderr, "\nCANCEL request sent\n"); + { + safe_write_stderr("\nCANCEL request sent\n"); + } else { - fprintf(stderr, "\nCannot send cancel request:\n%s\n", - PQerrorMessage(cancelConn)); + safe_write_stderr("\nCannot send cancel request:\n"); + safe_write_stderr(PQerrorMessage(cancelConn)); } } |