Add support for file birth/creation times on platforms that have it

Fixes #19

7 files changed, 145 insertions, 60 deletions

diff --git a/bfs.1 b/bfs.1
index f49e505..a6ff153 100644
--- a/bfs.1
+++ b/bfs.1
@@ -391,8 +391,8 @@ time of
 and
 .I Y
 can be any of
-.RI [ acm ]
-.RI ( a ccess/ c hange/ m odification).
+.RI [ aBcm ]
+.RI ( a ccess/ B irth/ c hange/ m odification).
 .TP
 \fB\-regex \fIREGEX\fR
 Find files whose entire path matches the regular expression
@@ -523,6 +523,23 @@ Treat
 as a path to search (useful if it begins with a dash).
 .LP
 Tests:
+.PP
+\fB\-Bmin\fR [\fI\-+\fR]\fIN\fR
+.br
+\fB\-Btime\fR [\fI\-+\fR]\fIN\fR
+.RS
+Find files
+.BR B irthed
+.I N
+minutes/days ago.
+.RE
+.TP
+\fB\-Bnewer \fIFILE\fR
+Find files
+.BR B irthed
+more recently than
+.I FILE
+was modified.
 .TP
 \fB\-depth\fR [\fI\-+\fR]\fIN\fR
 Find files with depth
diff --git a/eval.c b/eval.c
index 62dbf55..fe89225 100644
--- a/eval.c
+++ b/eval.c
@@ -135,15 +135,15 @@ bool eval_access(const struct expr *expr, struct eval_state *state) {
 }
 
 /**
- * -[acm]{min,time} tests.
+ * -[aBcm]?newer tests.
  */
-bool eval_acmtime(const struct expr *expr, struct eval_state *state) {
+bool eval_newer(const struct expr *expr, struct eval_state *state) {
 	const struct stat *statbuf = fill_statbuf(state);
 	if (!statbuf) {
 		return false;
 	}
 
-	const struct timespec *time = NULL;
+	const struct timespec *time;
 	switch (expr->time_field) {
 	case ATIME:
 		time = &statbuf->st_atim;
@@ -154,32 +154,32 @@ bool eval_acmtime(const struct expr *expr, struct eval_state *state) {
 	case MTIME:
 		time = &statbuf->st_mtim;
 		break;
-	}
-	assert(time);
 
-	time_t diff = timespec_diff(&expr->reftime, time);
-	switch (expr->time_unit) {
-	case MINUTES:
-		diff /= 60;
-		break;
-	case DAYS:
-		diff /= 60*60*24;
+#if BFS_HAVE_ST_BIRTHTIM
+	case BTIME:
+		time = &statbuf->st_birthtim;
 		break;
+#endif
+
+	default:
+		assert(false);
+		return false;
 	}
 
-	return expr_cmp(expr, diff);
+	return time->tv_sec > expr->reftime.tv_sec
+		|| (time->tv_sec == expr->reftime.tv_sec && time->tv_nsec > expr->reftime.tv_nsec);
 }
 
 /**
- * -[ac]?newer tests.
+ * -[aBcm]{min,time} tests.
  */
-bool eval_acnewer(const struct expr *expr, struct eval_state *state) {
+bool eval_time(const struct expr *expr, struct eval_state *state) {
 	const struct stat *statbuf = fill_statbuf(state);
 	if (!statbuf) {
 		return false;
 	}
 
-	const struct timespec *time = NULL;
+	const struct timespec *time;
 	switch (expr->time_field) {
 	case ATIME:
 		time = &statbuf->st_atim;
@@ -190,11 +190,29 @@ bool eval_acnewer(const struct expr *expr, struct eval_state *state) {
 	case MTIME:
 		time = &statbuf->st_mtim;
 		break;
+
+#if BFS_HAVE_ST_BIRTHTIM
+	case BTIME:
+		time = &statbuf->st_birthtim;
+		break;
+#endif
+
+	default:
+		assert(false);
+		return false;
 	}
-	assert(time);
 
-	return time->tv_sec > expr->reftime.tv_sec
-		|| (time->tv_sec == expr->reftime.tv_sec && time->tv_nsec > expr->reftime.tv_nsec);
+	time_t diff = timespec_diff(&expr->reftime, time);
+	switch (expr->time_unit) {
+	case MINUTES:
+		diff /= 60;
+		break;
+	case DAYS:
+		diff /= 60*60*24;
+		break;
+	}
+
+	return expr_cmp(expr, diff);
 }
 
 /**
diff --git a/eval.h b/eval.h
index 356f332..f190703 100644
--- a/eval.h
+++ b/eval.h
@@ -26,8 +26,8 @@ bool eval_false(const struct expr *expr, struct eval_state *state);
 bool eval_access(const struct expr *expr, struct eval_state *state);
 bool eval_perm(const struct expr *expr, struct eval_state *state);
 
-bool eval_acmtime(const struct expr *expr, struct eval_state *state);
-bool eval_acnewer(const struct expr *expr, struct eval_state *state);
+bool eval_newer(const struct expr *expr, struct eval_state *state);
+bool eval_time(const struct expr *expr, struct eval_state *state);
 bool eval_used(const struct expr *expr, struct eval_state *state);
 
 bool eval_gid(const struct expr *expr, struct eval_state *state);
diff --git a/expr.h b/expr.h
index 0eba0da..5581bf4 100644
--- a/expr.h
+++ b/expr.h
@@ -82,6 +82,8 @@ enum time_field {
 	CTIME,
 	/** Modification time. */
 	MTIME,
+	/** Birth time. */
+	BTIME,
 };
 
 /**
diff --git a/parse.c b/parse.c
index 6492412..9d533ab 100644
--- a/parse.c
+++ b/parse.c
@@ -893,38 +893,57 @@ static struct expr *parse_access(struct parser_state *state, int flag, int arg2)
 }
 
 /**
- * Parse -[acm]{min,time}.
+ * Parse -[aBcm]?newer.
  */
-static struct expr *parse_acmtime(struct parser_state *state, int field, int unit) {
-	struct expr *expr = parse_test_icmp(state, eval_acmtime);
-	if (expr) {
-		expr->cost = STAT_COST;
-		expr->reftime = state->now;
-		expr->time_field = field;
-		expr->time_unit = unit;
+static struct expr *parse_newer(struct parser_state *state, int field, int arg2) {
+	struct expr *expr = parse_unary_test(state, eval_newer);
+	if (!expr) {
+		return NULL;
+	}
+
+#if !BFS_HAVE_ST_BIRTHTIM
+	if (field == BTIME) {
+		cfprintf(state->cmdline->cerr, "%{er}error: %s: File birth times are not supported on this platform.%{rs}\n", expr->argv[0]);
+		goto fail;
+	}
+#endif
+
+	struct stat sb;
+	if (stat_arg(state, expr, &sb) != 0) {
+		goto fail;
 	}
+
+	expr->cost = STAT_COST;
+	expr->reftime = sb.st_mtim;
+	expr->time_field = field;
 	return expr;
+
+fail:
+	free_expr(expr);
+	return NULL;
 }
 
 /**
- * Parse -[ac]?newer.
+ * Parse -[aBcm]{min,time}.
  */
-static struct expr *parse_acnewer(struct parser_state *state, int field, int arg2) {
-	struct expr *expr = parse_unary_test(state, eval_acnewer);
+static struct expr *parse_time(struct parser_state *state, int field, int unit) {
+	struct expr *expr = parse_test_icmp(state, eval_time);
 	if (!expr) {
 		return NULL;
 	}
 
-	struct stat sb;
-	if (stat_arg(state, expr, &sb) != 0) {
+#if !BFS_HAVE_ST_BIRTHTIM
+	if (field == BTIME) {
+		cfprintf(state->cmdline->cerr, "%{er}error: %s: File birth times are not supported on this platform.%{rs}\n", expr->argv[0]);
 		free_expr(expr);
 		return NULL;
 	}
+#endif
 
 	expr->cost = STAT_COST;
-	expr->reftime = sb.st_mtim;
+	expr->reftime = state->now;
 	expr->time_field = field;
-
+	expr->time_unit = unit;
 	return expr;
 }
 
@@ -1445,13 +1464,15 @@ static struct expr *parse_lname(struct parser_state *state, int casefold, int ar
  * Parse -newerXY.
  */
 static struct expr *parse_newerxy(struct parser_state *state, int arg1, int arg2) {
+	CFILE *cerr = state->cmdline->cerr;
+
 	const char *arg = state->argv[0];
 	if (strlen(arg) != 8) {
-		cfprintf(state->cmdline->cerr, "%{er}error: Expected -newerXY; found %s.%{rs}\n", arg);
+		cfprintf(cerr, "%{er}error: Expected -newerXY; found %s.%{rs}\n", arg);
 		return NULL;
 	}
 
-	struct expr *expr = parse_unary_test(state, eval_acnewer);
+	struct expr *expr = parse_unary_test(state, eval_newer);
 	if (!expr) {
 		goto fail;
 	}
@@ -1468,16 +1489,21 @@ static struct expr *parse_newerxy(struct parser_state *state, int arg1, int arg2
 		break;
 
 	case 'B':
-		cfprintf(state->cmdline->cerr, "%{er}error: %s: File birth times ('B') are not supported.%{rs}\n", arg);
+#if BFS_HAVE_ST_BIRTHTIM
+		expr->time_field = BTIME;
+		break;
+#else
+		cfprintf(cerr, "%{er}error: %s: File birth times ('B') are not supported on this platform.%{rs}\n", arg);
 		goto fail;
+#endif
 
 	default:
-		cfprintf(state->cmdline->cerr, "%{er}error: %s: For -newerXY, X should be 'a', 'c', 'm', or 'B'.%{rs}\n", arg);
+		cfprintf(cerr, "%{er}error: %s: For -newerXY, X should be 'a', 'c', 'm', or 'B'.%{rs}\n", arg);
 		goto fail;
 	}
 
 	if (arg[7] == 't') {
-		cfprintf(state->cmdline->cerr, "%{er}error: %s: Explicit reference times ('t') are not supported.%{rs}\n", arg);
+		cfprintf(cerr, "%{er}error: %s: Explicit reference times ('t') are not supported.%{rs}\n", arg);
 		goto fail;
 	} else {
 		struct stat sb;
@@ -1497,12 +1523,15 @@ static struct expr *parse_newerxy(struct parser_state *state, int arg1, int arg2
 			break;
 
 		case 'B':
-			cfprintf(state->cmdline->cerr, "%{er}error: %s: File birth times ('B') are not supported.%{rs}\n", arg);
+#if BFS_HAVE_ST_BIRTHTIM
+			expr->reftime = sb.st_birthtim;
+#else
+			cfprintf(cerr, "%{er}error: %s: File birth times ('B') are not supported on this platform.%{rs}\n", arg);
 			goto fail;
+#endif
 
 		default:
-			cfprintf(state->cmdline->cerr,
-			         "%{er}error: %s: For -newerXY, Y should be 'a', 'c', 'm', 'B', or 't'.%{rs}\n", arg);
+			cfprintf(cerr, "%{er}error: %s: For -newerXY, Y should be 'a', 'c', 'm', 'B', or 't'.%{rs}\n", arg);
 			goto fail;
 		}
 	}
@@ -2310,7 +2339,7 @@ static struct expr *parse_help(struct parser_state *state, int arg1, int arg2) {
 	cfprintf(cout, "  %{blu}-newer%{rs}%{bld}XY%{rs} %{bld}REFERENCE%{rs}\n");
 	cfprintf(cout, "      Find files whose %{bld}X%{rs} time is newer than the %{bld}Y%{rs} time of"
 	               " %{bld}REFERENCE%{rs}.  %{bld}X%{rs} and %{bld}Y%{rs}\n");
-	cfprintf(cout, "      can be any of [acm].\n");
+	cfprintf(cout, "      can be any of [aBcm].\n");
 	cfprintf(cout, "  %{blu}-regex%{rs} %{bld}REGEX%{rs}\n");
 	cfprintf(cout, "      Find files whose entire path matches the regular expression %{bld}REGEX%{rs}\n");
 	cfprintf(cout, "  %{blu}-samefile%{rs} %{bld}FILE%{rs}\n");
@@ -2375,6 +2404,11 @@ static struct expr *parse_help(struct parser_state *state, int arg1, int arg2) {
 	cfprintf(cout, "  %{cyn}-f%{rs} %{mag}PATH%{rs}\n");
 	cfprintf(cout, "      Treat %{mag}PATH%{rs} as a path to search (useful if begins with a dash)\n\n");
 
+	cfprintf(cout, "  %{blu}-Bmin%{rs} %{bld}[-+]N%{rs}\n");
+	cfprintf(cout, "  %{blu}-Btime%{rs} %{bld}[-+]N%{rs}\n");
+	cfprintf(cout, "      Find files Birthed %{bld}N%{rs} minutes/days ago\n");
+	cfprintf(cout, "  %{blu}-Bnewer%{rs} %{bld}FILE%{rs}\n");
+	cfprintf(cout, "      Find files Birthed more recently than %{bld}FILEa%{rs} was modified\n");
 	cfprintf(cout, "  %{blu}-depth%{rs} %{bld}[-+]N%{rs}\n");
 	cfprintf(cout, "      Find files with depth %{bld}N%{rs}\n");
 	cfprintf(cout, "  %{blu}-gid%{rs} %{bld}NAME%{rs}\n");
@@ -2451,6 +2485,9 @@ struct table_entry {
  * The parse table for literals.
  */
 static const struct table_entry parse_table[] = {
+	{"-Bmin", false, parse_time, BTIME, MINUTES},
+	{"-Bnewer", false, parse_newer, BTIME},
+	{"-Btime", false, parse_time, BTIME, DAYS},
 	{"-D", false, parse_debug},
 	{"-E", false, parse_regex_extended},
 	{"-O", true, parse_optlevel},
@@ -2459,13 +2496,13 @@ static const struct table_entry parse_table[] = {
 	{"-L", false, parse_follow, BFTW_LOGICAL | BFTW_DETECT_CYCLES, false},
 	{"-X", false, parse_xargs_safe},
 	{"-a"},
-	{"-amin", false, parse_acmtime, ATIME, MINUTES},
+	{"-amin", false, parse_time, ATIME, MINUTES},
 	{"-and"},
-	{"-atime", false, parse_acmtime, ATIME, DAYS},
-	{"-anewer", false, parse_acnewer, ATIME},
-	{"-cmin", false, parse_acmtime, CTIME, MINUTES},
-	{"-ctime", false, parse_acmtime, CTIME, DAYS},
-	{"-cnewer", false, parse_acnewer, CTIME},
+	{"-anewer", false, parse_newer, ATIME},
+	{"-atime", false, parse_time, ATIME, DAYS},
+	{"-cmin", false, parse_time, CTIME, MINUTES},
+	{"-cnewer", false, parse_newer, CTIME},
+	{"-ctime", false, parse_time, CTIME, DAYS},
 	{"-color", false, parse_color, true},
 	{"-d", false, parse_depth},
 	{"-daystart", false, parse_daystart},
@@ -2500,12 +2537,12 @@ static const struct table_entry parse_table[] = {
 	{"-ls", false, parse_ls},
 	{"-maxdepth", false, parse_depth_limit, false},
 	{"-mindepth", false, parse_depth_limit, true},
-	{"-mmin", false, parse_acmtime, MTIME, MINUTES},
-	{"-mnewer", false, parse_acnewer, MTIME},
+	{"-mmin", false, parse_time, MTIME, MINUTES},
+	{"-mnewer", false, parse_newer, MTIME},
 	{"-mount", false, parse_mount},
-	{"-mtime", false, parse_acmtime, MTIME, DAYS},
+	{"-mtime", false, parse_time, MTIME, DAYS},
 	{"-name", false, parse_name, false},
-	{"-newer", false, parse_acnewer, MTIME},
+	{"-newer", false, parse_newer, MTIME},
 	{"-newer", true, parse_newerxy},
 	{"-nocolor", false, parse_color, false},
 	{"-nogroup", false, parse_nogroup},
diff --git a/printf.c b/printf.c
index 3c32108..9157ccb 100644
--- a/printf.c
+++ b/printf.c
@@ -87,10 +87,16 @@ static const struct timespec *get_time_field(const struct stat *statbuf, enum ti
 		return &statbuf->st_ctim;
 	case MTIME:
 		return &statbuf->st_mtim;
-	}
 
-	assert(false);
-	return NULL;
+#ifdef BFS_HAVE_ST_BIRTHTIM
+	case BTIME:
+		return &statbuf->st_birthtim;
+#endif
+
+	default:
+		assert(false);
+		return NULL;
+	}
 }
 
 /** %c, %c, and %t: ctime() */
diff --git a/util.h b/util.h
index 8f285d3..50f476e 100644
--- a/util.h
+++ b/util.h
@@ -32,6 +32,11 @@
 #	define st_atim st_atimespec
 #	define st_ctim st_ctimespec
 #	define st_mtim st_mtimespec
+#	define st_birthtim st_birthtimespec
+#endif
+
+#if __APPLE__ || __FreeBSD__ || __NetBSD__
+#	define BFS_HAVE_ST_BIRTHTIM true
 #endif
 
 #if !defined(FNM_CASEFOLD) && defined(FNM_IGNORECASE)