pg_ctl: improve handling of invalid data directory

Return '4' and report a meaningful error message when a non-existent or
invalid data directory is passed.  Previously, pg_ctl would just report
the server was not running.

Patch by me and Amit Kapila
Report from Peter Eisentraut

diff --git a/doc/src/sgml/ref/pg_ctl-ref.sgml b/doc/src/sgml/ref/pg_ctl-ref.sgml
index 45b53ce1a1a6920641a7b1b34f0c908546d429b6..52bcf5e81538ee8085febae0c9f615a7ce3a9248 100644 (file)
--- a/doc/src/sgml/ref/pg_ctl-ref.sgml
+++ b/doc/src/sgml/ref/pg_ctl-ref.sgml
@@ -208,7 +208,8 @@ PostgreSQL documentation
    the specified data directory. If it is, the <acronym>PID</acronym>
    and the command line options that were used to invoke it are
    displayed.  If the server is not running, the process returns an
-   exit status of 3.
+   exit status of 3.  If an accessible data directory is not specified,
+   the process returns an exit status of 4.
   </para>
 
   <para>

diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index 0dbaa6e27fe5009d7f0e95710309bc7056779c61..56d238f39481da3c8bd5043e8889a3e58cfdca84 100644 (file)
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -97,6 +97,7 @@ static bool allow_core_files = false;
 static time_t start_time;
 
 static char postopts_file[MAXPGPATH];
+static char version_file[MAXPGPATH];
 static char pid_file[MAXPGPATH];
 static char backup_file[MAXPGPATH];
 static char recovery_file[MAXPGPATH];
@@ -152,7 +153,7 @@ static void pgwin32_doRunAsService(void);
 static int     CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_service);
 #endif
 
-static pgpid_t get_pgpid(void);
+static pgpid_t get_pgpid(bool is_status_request);
 static char **readfile(const char *path);
 static void free_readfile(char **optlines);
 static int     start_postmaster(void);
@@ -246,10 +247,34 @@ print_msg(const char *msg)
 }
 
 static pgpid_t
-get_pgpid(void)
+get_pgpid(bool is_status_request)
 {
        FILE       *pidf;
        long            pid;
+       struct stat statbuf;
+
+       if (stat(pg_data, &statbuf) != 0)
+       {
+               if (errno == ENOENT)
+                       printf(_("%s: directory \"%s\" does not exist\n"), progname,
+                                        pg_data);
+               else
+                       printf(_("%s: cannot access directory \"%s\"\n"), progname,
+                                        pg_data);
+               /*
+                * The Linux Standard Base Core Specification 3.1 says this should return
+                * '4, program or service status is unknown'
+                * https://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html
+                */
+               exit(is_status_request ? 4 : 1);
+       }
+
+       if (stat(version_file, &statbuf) != 0 && errno == ENOENT)
+       {
+               printf(_("%s: directory \"%s\" is not a database cluster directory\n"),
+                                progname, pg_data);
+               exit(is_status_request ? 4 : 1);
+       }
 
        pidf = fopen(pid_file, "r");
        if (pidf == NULL)
@@ -810,7 +835,7 @@ do_start(void)
 
        if (ctl_command != RESTART_COMMAND)
        {
-               old_pid = get_pgpid();
+               old_pid = get_pgpid(false);
                if (old_pid != 0)
                        write_stderr(_("%s: another server might be running; "
                                                   "trying to start server anyway\n"),
@@ -894,7 +919,7 @@ do_stop(void)
        pgpid_t         pid;
        struct stat statbuf;
 
-       pid = get_pgpid();
+       pid = get_pgpid(false);
 
        if (pid == 0)                           /* no pid file */
        {
@@ -943,7 +968,7 @@ do_stop(void)
 
                for (cnt = 0; cnt < wait_seconds; cnt++)
                {
-                       if ((pid = get_pgpid()) != 0)
+                       if ((pid = get_pgpid(false)) != 0)
                        {
                                print_msg(".");
                                pg_usleep(1000000);             /* 1 sec */
@@ -980,7 +1005,7 @@ do_restart(void)
        pgpid_t         pid;
        struct stat statbuf;
 
-       pid = get_pgpid();
+       pid = get_pgpid(false);
 
        if (pid == 0)                           /* no pid file */
        {
@@ -1033,7 +1058,7 @@ do_restart(void)
 
                for (cnt = 0; cnt < wait_seconds; cnt++)
                {
-                       if ((pid = get_pgpid()) != 0)
+                       if ((pid = get_pgpid(false)) != 0)
                        {
                                print_msg(".");
                                pg_usleep(1000000);             /* 1 sec */
@@ -1071,7 +1096,7 @@ do_reload(void)
 {
        pgpid_t         pid;
 
-       pid = get_pgpid();
+       pid = get_pgpid(false);
        if (pid == 0)                           /* no pid file */
        {
                write_stderr(_("%s: PID file \"%s\" does not exist\n"), progname, pid_file);
@@ -1110,7 +1135,7 @@ do_promote(void)
        pgpid_t         pid;
        struct stat statbuf;
 
-       pid = get_pgpid();
+       pid = get_pgpid(false);
 
        if (pid == 0)                           /* no pid file */
        {
@@ -1204,7 +1229,7 @@ do_status(void)
 {
        pgpid_t         pid;
 
-       pid = get_pgpid();
+       pid = get_pgpid(true);
        /* Is there a pid file? */
        if (pid != 0)
        {
@@ -1247,7 +1272,7 @@ do_status(void)
 
        /*
         * The Linux Standard Base Core Specification 3.1 says this should return
-        * '3'
+        * '3, program is not running'
         * https://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html
         */
        exit(3);
@@ -2285,6 +2310,7 @@ main(int argc, char **argv)
        if (pg_data)
        {
                snprintf(postopts_file, MAXPGPATH, "%s/postmaster.opts", pg_data);
+               snprintf(version_file, MAXPGPATH, "%s/PG_VERSION", pg_data);
                snprintf(pid_file, MAXPGPATH, "%s/postmaster.pid", pg_data);
                snprintf(backup_file, MAXPGPATH, "%s/backup_label", pg_data);
                snprintf(recovery_file, MAXPGPATH, "%s/recovery.conf", pg_data);