*
* Copyright (c) 2000-2009, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/bin/psql/input.c,v 1.66 2009/01/01 17:23:55 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/input.c,v 1.67 2009/09/13 22:18:22 tgl Exp $
*/
#include "postgres_fe.h"
+#ifndef WIN32
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+
#include "input.h"
#include "settings.h"
#include "tab-complete.h"
#ifdef USE_READLINE
static bool useReadline;
static bool useHistory;
-char *psql_history;
+
+static char *psql_history;
+
+static int history_lines_added;
+
/*
* Preserve newlines in saved queries by mapping '\n' to NL_IN_HISTORY
prev_hist = pg_strdup(s);
/* And send it to readline */
add_history(s);
+ /* Count lines added to history for use later */
+ history_lines_added++;
}
}
useHistory = true;
using_history();
+ history_lines_added = 0;
histfile = GetVariable(pset.vars, "HISTFILE");
if (histfile == NULL)
/*
- * This function is for saving the readline history when user
- * runs \s command or when psql finishes.
+ * This function saves the readline history when user
+ * runs \s command or when psql exits.
+ *
+ * fname: pathname of history file. (Should really be "const char *",
+ * but some ancient versions of readline omit the const-decoration.)
+ *
+ * max_lines: if >= 0, limit history file to that many entries.
*
- * We have an argument named encodeFlag to handle the cases differently.
- * In case of call via \s we don't really need to encode \n as \x01,
- * but when we save history for Readline we must do that conversion.
+ * appendFlag: if true, try to append just our new lines to the file.
+ * If false, write the whole available history.
+ *
+ * encodeFlag: whether to encode \n as \x01. For \s calls we don't wish
+ * to do that, but must do so when saving the final history file.
*/
bool
-saveHistory(char *fname, bool encodeFlag)
+saveHistory(char *fname, int max_lines, bool appendFlag, bool encodeFlag)
{
#ifdef USE_READLINE
encode_history();
/*
- * return value of write_history is not standardized across GNU
+ * On newer versions of libreadline, truncate the history file as
+ * needed and then append what we've added. This avoids overwriting
+ * history from other concurrent sessions (although there are still
+ * race conditions when two sessions exit at about the same time).
+ * If we don't have those functions, fall back to write_history().
+ *
+ * Note: return value of write_history is not standardized across GNU
* readline and libedit. Therefore, check for errno becoming set to
- * see if the write failed.
+ * see if the write failed. Similarly for append_history.
*/
- errno = 0;
- (void) write_history(fname);
- if (errno == 0)
- return true;
+#if defined(HAVE_HISTORY_TRUNCATE_FILE) && defined(HAVE_APPEND_HISTORY)
+ if (appendFlag)
+ {
+ int nlines;
+ int fd;
+
+ /* truncate previous entries if needed */
+ if (max_lines >= 0)
+ {
+ nlines = Max(max_lines - history_lines_added, 0);
+ (void) history_truncate_file(fname, nlines);
+ }
+ /* append_history fails if file doesn't already exist :-( */
+ fd = open(fname, O_CREAT | O_WRONLY | PG_BINARY, 0600);
+ if (fd >= 0)
+ close(fd);
+ /* append the appropriate number of lines */
+ if (max_lines >= 0)
+ nlines = Min(max_lines, history_lines_added);
+ else
+ nlines = history_lines_added;
+ errno = 0;
+ (void) append_history(nlines, fname);
+ if (errno == 0)
+ return true;
+ }
+ else
+#endif
+ {
+ /* truncate what we have ... */
+ if (max_lines >= 0)
+ stifle_history(max_lines);
+ /* ... and overwrite file. Tough luck for concurrent sessions. */
+ errno = 0;
+ (void) write_history(fname);
+ if (errno == 0)
+ return true;
+ }
psql_error("could not save history to file \"%s\": %s\n",
fname, strerror(errno));
int hist_size;
hist_size = GetVariableNum(pset.vars, "HISTSIZE", 500, -1, true);
- if (hist_size >= 0)
- stifle_history(hist_size);
-
- saveHistory(psql_history, true);
+ saveHistory(psql_history, hist_size, true, true);
free(psql_history);
psql_history = NULL;
}
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