From bc478a0a85bc8660bfa251866f85c673e4be84ac Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 12 May 2023 16:11:14 -0400 Subject: Tighten usage of PSQL_WATCH_PAGER. Don't use PSQL_WATCH_PAGER when stdin/stdout are not a terminal. This corresponds to the restrictions on when other commands will use [PSQL_]PAGER. There isn't a lot of sense in trying to use a pager in non-interactive cases, and doing so allows an environment setting to break our tests. Also, ignore PSQL_WATCH_PAGER if it is set but empty or all-blank, for the same reasons we ignore such settings of [PSQL_]PAGER (see commit 18f8f784c). No documentation change is really needed, since there is nothing suggesting that these constraints on [PSQL_]PAGER didn't already apply to PSQL_WATCH_PAGER too. But I rearranged the text a little to make it read more naturally (IMHO anyway). Per report from Pavel Stehule. Back-patch to v15 where PSQL_WATCH_PAGER was introduced. Discussion: https://postgr.es/m/CAFj8pRDTwFzmEWdA-gdAcUh0ZnxUioSfTMre71WyB_wNJy-8gw@mail.gmail.com --- src/bin/psql/command.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c index bb94df50a63..897fbee8d6c 100644 --- a/src/bin/psql/command.c +++ b/src/bin/psql/command.c @@ -5020,14 +5020,20 @@ do_watch(PQExpBuffer query_buf, double sleep) /* * For \watch, we ignore the size of the result and always use the pager - * if PSQL_WATCH_PAGER is set. We also ignore the regular PSQL_PAGER or - * PAGER environment variables, because traditional pagers probably won't - * be very useful for showing a stream of results. + * as long as we're talking to a terminal and "\pset pager" is enabled. + * However, we'll only use the pager identified by PSQL_WATCH_PAGER. We + * ignore the regular PSQL_PAGER or PAGER environment variables, because + * traditional pagers probably won't be very useful for showing a stream + * of results. */ #ifdef HAVE_POSIX_DECL_SIGWAIT pagerprog = getenv("PSQL_WATCH_PAGER"); + /* if variable is empty or all-white-space, don't use pager */ + if (pagerprog && strspn(pagerprog, " \t\r\n") == strlen(pagerprog)) + pagerprog = NULL; #endif - if (pagerprog && myopt.topt.pager) + if (pagerprog && myopt.topt.pager && + isatty(fileno(stdin)) && isatty(fileno(stdout))) { disable_sigpipe_trap(); pagerpipe = popen(pagerprog, "w"); -- cgit v1.2.3