Add \ir command to psql.

\ir is short for "include relative"; when used from a script, the
supplied pathname will be interpreted relative to the input file,
rather than to the current working directory.

Gurjeet Singh, reviewed by Josh Kupershmidt, with substantial further
cleanup by me.

doc/src/sgml/ref/psql-ref.sgml

@@ -1625,6 +1625,21 @@ Tue Oct 26 21:40:57 CEST 1999
       </varlistentry>
 
 
+      <varlistentry>
+        <term><literal>\ir <replaceable class="parameter">filename</replaceable></literal></term>
+        <listitem>
+        <para>
+        The <literal>\ir</> command is similar to <literal>\i</>, but resolves
+        relative pathnames differently.  When executing in interactive mode,
+        the two commands behave identically.  However, when invoked from a
+        script, <literal>\ir</literal> interprets pathnames relative to the
+        directory in which the script is located, rather than the current
+        working directory.
+        </para>
+        </listitem>
+      </varlistentry>
+
+
       <varlistentry>
         <term><literal>\l</literal> (or <literal>\list</literal>)</term>
         <term><literal>\l+</literal> (or <literal>\list+</literal>)</term>

src/bin/psql/command.c

@@ -784,8 +784,9 @@ exec_command(const char *cmd,
 	}
 
 
-	/* \i is include file */
+	/* \i and \ir include files */
-	else if (strcmp(cmd, "i") == 0 || strcmp(cmd, "include") == 0)
+	else if (strcmp(cmd, "i") == 0 || strcmp(cmd, "include") == 0
+			|| strcmp(cmd, "ir") == 0 || strcmp(cmd, "include_relative") == 0)
 	{
 		char	   *fname = psql_scan_slash_option(scan_state,
 												   OT_NORMAL, NULL, true);
@@ -797,8 +798,12 @@ exec_command(const char *cmd,
 		}
 		else
 		{
+			bool	include_relative;
+
+			include_relative = (strcmp(cmd, "ir") == 0
+								|| strcmp(cmd, "include_relative") == 0);
 			expand_tilde(&fname);
-			success = (process_file(fname, false) == EXIT_SUCCESS);
+			success = (process_file(fname, false, include_relative) == EXIT_SUCCESS);
 			free(fname);
 		}
 	}
@@ -1969,15 +1974,19 @@ do_edit(const char *filename_arg, PQExpBuffer query_buf,
  * process_file
  *
  * Read commands from filename and then them to the main processing loop
- * Handler for \i, but can be used for other things as well.  Returns
+ * Handler for \i and \ir, but can be used for other things as well.  Returns
  * MainLoop() error code.
+ *
+ * If use_relative_path is true and filename is not an absolute path, then open
+ * the file from where the currently processed file (if any) is located.
  */
 int
-process_file(char *filename, bool single_txn)
+process_file(char *filename, bool single_txn, bool use_relative_path)
 {
 	FILE	   *fd;
 	int			result;
 	char	   *oldfilename;
+	char		relpath[MAXPGPATH];
 	PGresult   *res;
 
 	if (!filename)
@@ -1986,6 +1995,24 @@ process_file(char *filename, bool single_txn)
 	if (strcmp(filename, "-") != 0)
 	{
 		canonicalize_path(filename);
+
+		/*
+		 * If we were asked to resolve the pathname relative to the location
+		 * of the currently executing script, and there is one, and this is
+		 * a relative pathname, then prepend all but the last pathname
+		 * component of the current script to this pathname.
+		 */
+		if (use_relative_path && pset.inputfile && !is_absolute_path(filename)
+			&& !has_drive_prefix(filename))
+		{
+			snprintf(relpath, MAXPGPATH, "%s", pset.inputfile);
+			get_parent_directory(relpath);
+			join_path_components(relpath, relpath, filename);
+			canonicalize_path(relpath);
+
+			filename = relpath;
+		}
+
 		fd = fopen(filename, PG_BINARY_R);
 	}
 	else

src/bin/psql/command.h

@@ -27,7 +27,7 @@ typedef enum _backslashResult
 extern backslashResult HandleSlashCmds(PsqlScanState scan_state,
 				PQExpBuffer query_buf);
 
-extern int	process_file(char *filename, bool single_txn);
+extern int	process_file(char *filename, bool single_txn, bool use_relative_path);
 
 extern bool do_pset(const char *param,
 		const char *value,

src/bin/psql/help.c

@@ -158,7 +158,7 @@ slashUsage(unsigned short int pager)
 {
 	FILE	   *output;
 
-	output = PageOutput(92, pager);
+	output = PageOutput(93, pager);
 
 	/* if you add/remove a line here, change the row count above */
 
@@ -184,6 +184,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\copy ...              perform SQL COPY with data stream to the client host\n"));
 	fprintf(output, _("  \\echo [STRING]         write string to standard output\n"));
 	fprintf(output, _("  \\i FILE                execute commands from file\n"));
+	fprintf(output, _("  \\ir FILE               as \\i, but relative to location of current script\n"));
 	fprintf(output, _("  \\o [FILE]              send all query results to file or |pipe\n"));
 	fprintf(output, _("  \\qecho [STRING]        write string to query output stream (see \\o)\n"));
 	fprintf(output, "\n");

src/bin/psql/settings.h

@@ -81,7 +81,7 @@ typedef struct _psqlSettings
 	bool		cur_cmd_interactive;
 	int			sversion;		/* backend server version */
 	const char *progname;		/* in case you renamed psql */
-	char	   *inputfile;		/* for error reporting */
+	char	   *inputfile;		/* file being currently processed, if any */
 	char	   *dirname;		/* current directory for \s display */
 
 	uint64		lineno;			/* also for error reporting */

src/bin/psql/startup.c

@@ -256,7 +256,7 @@ main(int argc, char *argv[])
 		if (!options.no_psqlrc)
 			process_psqlrc(argv[0]);
 
-		successResult = process_file(options.action_string, options.single_txn);
+		successResult = process_file(options.action_string, options.single_txn, false);
 	}
 
 	/*
@@ -604,9 +604,9 @@ process_psqlrc_file(char *filename)
 	sprintf(psqlrc, "%s-%s", filename, PG_VERSION);
 
 	if (access(psqlrc, R_OK) == 0)
-		(void) process_file(psqlrc, false);
+		(void) process_file(psqlrc, false, false);
 	else if (access(filename, R_OK) == 0)
-		(void) process_file(filename, false);
+		(void) process_file(filename, false, false);
 	free(psqlrc);
 }
 

src/bin/psql/tab-complete.c

@@ -735,7 +735,7 @@ psql_completion(char *text, int start, int end)
 		"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
 		"\\dn", "\\do", "\\dp", "\\drds", "\\ds", "\\dS", "\\dt", "\\dT", "\\dv", "\\du",
 		"\\e", "\\echo", "\\ef", "\\encoding",
-		"\\f", "\\g", "\\h", "\\help", "\\H", "\\i", "\\l",
+		"\\f", "\\g", "\\h", "\\help", "\\H", "\\i", "\\ir", "\\l",
 		"\\lo_import", "\\lo_export", "\\lo_list", "\\lo_unlink",
 		"\\o", "\\p", "\\password", "\\prompt", "\\pset", "\\q", "\\qecho", "\\r",
 		"\\set", "\\sf", "\\t", "\\T",
@@ -2874,6 +2874,7 @@ psql_completion(char *text, int start, int end)
 			 strcmp(prev_wd, "\\e") == 0 || strcmp(prev_wd, "\\edit") == 0 ||
 			 strcmp(prev_wd, "\\g") == 0 ||
 		  strcmp(prev_wd, "\\i") == 0 || strcmp(prev_wd, "\\include") == 0 ||
+		  strcmp(prev_wd, "\\ir") == 0 || strcmp(prev_wd, "\\include_relative") == 0 ||
 			 strcmp(prev_wd, "\\o") == 0 || strcmp(prev_wd, "\\out") == 0 ||
 			 strcmp(prev_wd, "\\s") == 0 ||
 			 strcmp(prev_wd, "\\w") == 0 || strcmp(prev_wd, "\\write") == 0

src/include/port.h

@@ -34,6 +34,7 @@ extern bool pg_set_block(pgsocket sock);
 
 /* Portable path handling for Unix/Win32 (in path.c) */
 
+extern bool has_drive_prefix(const char *filename);
 extern char *first_dir_separator(const char *filename);
 extern char *last_dir_separator(const char *filename);
 extern char *first_path_var_separator(const char *pathlist);

src/port/path.c

@@ -74,6 +74,17 @@ skip_drive(const char *path)
 #define skip_drive(path)	(path)
 #endif
 
+/*
+ *	has_drive_prefix
+ *
+ * Return true if the given pathname has a drive prefix.
+ */
+bool
+has_drive_prefix(const char *path)
+{
+	return skip_drive(path) != path;
+}
+
 /*
  *	first_dir_separator
  *