time: Split out time-related functions from util

9 files changed, 351 insertions, 278 deletions

diff --git a/Makefile b/Makefile
index f25fd12..d6183ab 100644
--- a/Makefile
+++ b/Makefile
@@ -89,6 +89,7 @@ bfs: \
     printf.o \
     spawn.o \
     stat.o \
+    time.o \
     trie.o \
     typo.o \
     util.o
diff --git a/eval.c b/eval.c
index ab885fc..23c7b1b 100644
--- a/eval.c
+++ b/eval.c
@@ -30,6 +30,7 @@
 #include "mtab.h"
 #include "printf.h"
 #include "stat.h"
+#include "time.h"
 #include "trie.h"
 #include "util.h"
 #include <assert.h>
diff --git a/main.c b/main.c
index abab187..b8d7bae 100644
--- a/main.c
+++ b/main.c
@@ -42,6 +42,7 @@
  *     - mtab.[ch]     (parses the system's mount table)
  *     - spawn.[ch]    (spawns processes)
  *     - stat.[ch]     (wraps stat(), or statx() on Linux)
+ *     - time.[ch]     (date/time handling utilities)
  *     - trie.[ch]     (a trie set/map implementation)
  *     - typo.[ch]     (fuzzy matching for typos)
  *     - util.[ch]     (everything else)
diff --git a/parse.c b/parse.c
index ada0ec2..509d835 100644
--- a/parse.c
+++ b/parse.c
@@ -34,6 +34,7 @@
 #include "printf.h"
 #include "spawn.h"
 #include "stat.h"
+#include "time.h"
 #include "typo.h"
 #include "util.h"
 #include <assert.h>
@@ -1635,147 +1636,19 @@ static enum bfs_stat_field parse_newerxy_field(char c) {
 	}
 }
 
-/** Parse some digits from an explicit reference time. */
-static int parse_timestamp_part(const struct parser_state *state, const char **str, size_t n, int *result, int delta) {
-	char buf[n + 1];
-	for (size_t i = 0; i < n; ++i, ++*str) {
-		char c = **str;
-		if (c < '0' || c > '9') {
-			return -1;
-		}
-		buf[i] = c;
-	}
-	buf[n] = '\0';
-
-	if (!parse_int(state, buf, result, IF_INT | IF_QUIET)) {
-		return -1;
-	}
-
-	*result += delta;
-	return 0;
-}
-
 /** Parse an explicit reference timestamp for -newerXt and -*since. */
-static int parse_timestamp(const struct parser_state *state, struct expr *expr) {
-	const char *str = expr->sdata;
-	struct tm tm = {
-		.tm_isdst = -1,
-	};
-
-	int tz_hour = 0;
-	int tz_min = 0;
-	bool tz_negative = false;
-	bool local = true;
-
-	// YYYY
-	if (parse_timestamp_part(state, &str, 4, &tm.tm_year, -1900) != 0) {
-		goto invalid;
-	}
-
-	// MM
-	if (*str == '-') {
-		++str;
-	}
-	if (parse_timestamp_part(state, &str, 2, &tm.tm_mon, -1) != 0) {
-		goto invalid;
-	}
-
-	// DD
-	if (*str == '-') {
-		++str;
-	}
-	if (parse_timestamp_part(state, &str, 2, &tm.tm_mday, 0) != 0) {
-		goto invalid;
-	}
-
-	if (!*str) {
-		goto end;
-	} else if (*str == 'T') {
-		++str;
-	}
-
-	// hh
-	if (parse_timestamp_part(state, &str, 2, &tm.tm_hour, 0) != 0) {
-		goto invalid;
-	}
-
-	// mm
-	if (!*str) {
-		goto end;
-	} else if (*str == ':') {
-		++str;
-	}
-	if (parse_timestamp_part(state, &str, 2, &tm.tm_min, 0) != 0) {
-		goto invalid;
-	}
-
-	// ss
-	if (!*str) {
-		goto end;
-	} else if (*str == ':') {
-		++str;
-	}
-	if (parse_timestamp_part(state, &str, 2, &tm.tm_sec, 0) != 0) {
-		goto invalid;
-	}
-
-	if (!*str) {
-		goto end;
-	} else if (*str == 'Z') {
-		local = false;
-		++str;
-	} else if (*str == '+' || *str == '-') {
-		local = false;
-		tz_negative = *str == '-';
-		++str;
-
-		// hh
-		if (parse_timestamp_part(state, &str, 2, &tz_hour, 0) != 0) {
-			goto invalid;
-		}
-
-		// mm
-		if (!*str) {
-			goto end;
-		} else if (*str == ':') {
-			++str;
-		}
-		if (parse_timestamp_part(state, &str, 2, &tz_min, 0) != 0) {
-			goto invalid;
-		}
-	} else {
-		goto invalid;
-	}
-
-	if (*str) {
-		goto invalid;
-	}
-
-end:
-	if (local) {
-		if (xmktime(&tm, &expr->reftime.tv_sec) != 0) {
-			goto error;
-		}
-	} else {
-		if (xtimegm(&tm, &expr->reftime.tv_sec) != 0) {
-			goto error;
-		}
-
-		int offset = 60*tz_hour + tz_min;
-		if (tz_negative) {
-			expr->reftime.tv_sec -= offset;
-		} else {
-			expr->reftime.tv_sec += offset;
-		}
+static int parse_reftime(const struct parser_state *state, struct expr *expr) {
+	if (parse_timestamp(expr->sdata, &expr->reftime) == 0) {
+		return 0;
+	} else if (errno != EINVAL) {
+		parse_error(state, "%s %s: %m.\n", expr->argv[0], expr->argv[1]);
+		return -1;
 	}
 
-	expr->reftime.tv_nsec = 0;
-	return 0;
-
-invalid:
 	parse_error(state, "%s %s: Invalid timestamp.\n\n", expr->argv[0], expr->argv[1]);
 	fprintf(stderr, "Supported timestamp formats are ISO 8601-like, e.g.\n\n");
 
+	struct tm tm;
 	if (xlocaltime(&state->now.tv_sec, &tm) != 0) {
 		perror("xlocaltime()");
 		return -1;
@@ -1787,12 +1660,12 @@ invalid:
 	fprintf(stderr, "  - %04d-%02d-%02dT%02d:%02d:%02d\n", year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
 
 #if __FreeBSD__
-	tz_hour = tm.tm_gmtoff/3600;
-	tz_min = (labs(tm.tm_gmtoff)/60)%60;
+	int gmtoff = tm.tm_gmtoff;
 #else
-	tz_hour = -timezone/3600;
-	tz_min = (labs(timezone)/60)%60;
+	int gmtoff = -timezone;
 #endif
+	int tz_hour = gmtoff/3600;
+	int tz_min = (labs(gmtoff)/60)%60;
 	fprintf(stderr, "  - %04d-%02d-%02dT%02d:%02d:%02d%+03d:%02d\n",
 	        year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, tz_hour, tz_min);
 
@@ -1806,10 +1679,6 @@ invalid:
 	fprintf(stderr, "  - %04d-%02d-%02dT%02d:%02d:%02dZ\n", year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
 
 	return -1;
-
-error:
-	parse_error(state, "%s %s: Error parsing timestamp: %m.\n", expr->argv[0], expr->argv[1]);
-	return -1;
 }
 
 /**
@@ -1834,7 +1703,7 @@ static struct expr *parse_newerxy(struct parser_state *state, int arg1, int arg2
 	}
 
 	if (arg[7] == 't') {
-		if (parse_timestamp(state, expr) != 0) {
+		if (parse_reftime(state, expr) != 0) {
 			goto fail;
 		}
 	} else {
@@ -2408,7 +2277,7 @@ static struct expr *parse_since(struct parser_state *state, int field, int arg2)
 		return NULL;
 	}
 
-	if (parse_timestamp(state, expr) != 0) {
+	if (parse_reftime(state, expr) != 0) {
 		goto fail;
 	}
 
diff --git a/printf.c b/printf.c
index 80f54c9..4e7af18 100644
--- a/printf.c
+++ b/printf.c
@@ -22,6 +22,7 @@
 #include "expr.h"
 #include "mtab.h"
 #include "stat.h"
+#include "time.h"
 #include "util.h"
 #include <assert.h>
 #include <errno.h>
diff --git a/time.c b/time.c
new file mode 100644
index 0000000..3575abd
--- /dev/null
+++ b/time.c
@@ -0,0 +1,247 @@
+/****************************************************************************
+ * bfs                                                                      *
+ * Copyright (C) 2020 Tavian Barnes <tavianator@tavianator.com>             *
+ *                                                                          *
+ * Permission to use, copy, modify, and/or distribute this software for any *
+ * purpose with or without fee is hereby granted.                           *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
+ ****************************************************************************/
+
+#include "time.h"
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+int xlocaltime(const time_t *timep, struct tm *result) {
+	// Should be called before localtime_r() according to POSIX.1-2004
+	tzset();
+
+	if (localtime_r(timep, result)) {
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+int xgmtime(const time_t *timep, struct tm *result) {
+	// Should be called before gmtime_r() according to POSIX.1-2004
+	tzset();
+
+	if (gmtime_r(timep, result)) {
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+int xmktime(struct tm *tm, time_t *timep) {
+	*timep = mktime(tm);
+
+	if (*timep == -1) {
+		int error = errno;
+
+		struct tm tmp;
+		if (xlocaltime(timep, &tmp) != 0) {
+			return -1;
+		}
+
+		if (tm->tm_year != tmp.tm_year || tm->tm_yday != tmp.tm_yday
+		    || tm->tm_hour != tmp.tm_hour || tm->tm_min != tmp.tm_min || tm->tm_sec != tmp.tm_sec) {
+			errno = error;
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int xtimegm(struct tm *tm, time_t *timep) {
+	// Some man pages for timegm() recommend this as a portable approach
+	int ret = -1;
+	int error;
+
+	char *old_tz = getenv("TZ");
+	if (old_tz) {
+		old_tz = strdup(old_tz);
+		if (!old_tz) {
+			error = errno;
+			goto fail;
+		}
+	}
+
+	if (setenv("TZ", "UTC0", true) != 0) {
+		error = errno;
+		goto fail;
+	}
+
+	ret = xmktime(tm, timep);
+	error = errno;
+
+	if (old_tz) {
+		if (setenv("TZ", old_tz, true) != 0) {
+			ret = -1;
+			error = errno;
+			goto fail;
+		}
+	} else {
+		if (unsetenv("TZ") != 0) {
+			ret = -1;
+			error = errno;
+			goto fail;
+		}
+	}
+
+	tzset();
+fail:
+	free(old_tz);
+	errno = error;
+	return ret;
+}
+
+/** Parse some digits from a timestamp. */
+static int parse_timestamp_part(const char **str, size_t n, int *result) {
+	char buf[n + 1];
+	for (size_t i = 0; i < n; ++i, ++*str) {
+		char c = **str;
+		if (c < '0' || c > '9') {
+			return -1;
+		}
+		buf[i] = c;
+	}
+	buf[n] = '\0';
+
+	*result = atoi(buf);
+	return 0;
+}
+
+int parse_timestamp(const char *str, struct timespec *result) {
+	struct tm tm = {
+		.tm_isdst = -1,
+	};
+
+	int tz_hour = 0;
+	int tz_min = 0;
+	bool tz_negative = false;
+	bool local = true;
+
+	// YYYY
+	if (parse_timestamp_part(&str, 4, &tm.tm_year) != 0) {
+		goto invalid;
+	}
+	tm.tm_year -= 1900;
+
+	// MM
+	if (*str == '-') {
+		++str;
+	}
+	if (parse_timestamp_part(&str, 2, &tm.tm_mon) != 0) {
+		goto invalid;
+	}
+	tm.tm_mon -= 1;
+
+	// DD
+	if (*str == '-') {
+		++str;
+	}
+	if (parse_timestamp_part(&str, 2, &tm.tm_mday) != 0) {
+		goto invalid;
+	}
+
+	if (!*str) {
+		goto end;
+	} else if (*str == 'T') {
+		++str;
+	}
+
+	// hh
+	if (parse_timestamp_part(&str, 2, &tm.tm_hour) != 0) {
+		goto invalid;
+	}
+
+	// mm
+	if (!*str) {
+		goto end;
+	} else if (*str == ':') {
+		++str;
+	}
+	if (parse_timestamp_part(&str, 2, &tm.tm_min) != 0) {
+		goto invalid;
+	}
+
+	// ss
+	if (!*str) {
+		goto end;
+	} else if (*str == ':') {
+		++str;
+	}
+	if (parse_timestamp_part(&str, 2, &tm.tm_sec) != 0) {
+		goto invalid;
+	}
+
+	if (!*str) {
+		goto end;
+	} else if (*str == 'Z') {
+		local = false;
+		++str;
+	} else if (*str == '+' || *str == '-') {
+		local = false;
+		tz_negative = *str == '-';
+		++str;
+
+		// hh
+		if (parse_timestamp_part(&str, 2, &tz_hour) != 0) {
+			goto invalid;
+		}
+
+		// mm
+		if (!*str) {
+			goto end;
+		} else if (*str == ':') {
+			++str;
+		}
+		if (parse_timestamp_part(&str, 2, &tz_min) != 0) {
+			goto invalid;
+		}
+	} else {
+		goto invalid;
+	}
+
+	if (*str) {
+		goto invalid;
+	}
+
+end:
+	if (local) {
+		if (xmktime(&tm, &result->tv_sec) != 0) {
+			goto error;
+		}
+	} else {
+		if (xtimegm(&tm, &result->tv_sec) != 0) {
+			goto error;
+		}
+
+		int offset = 60*tz_hour + tz_min;
+		if (tz_negative) {
+			result->tv_sec -= offset;
+		} else {
+			result->tv_sec += offset;
+		}
+	}
+
+	result->tv_nsec = 0;
+	return 0;
+
+invalid:
+	errno = EINVAL;
+error:
+	return -1;
+}
diff --git a/time.h b/time.h
new file mode 100644
index 0000000..0f9adb4
--- /dev/null
+++ b/time.h
@@ -0,0 +1,86 @@
+/****************************************************************************
+ * bfs                                                                      *
+ * Copyright (C) 2020 Tavian Barnes <tavianator@tavianator.com>             *
+ *                                                                          *
+ * Permission to use, copy, modify, and/or distribute this software for any *
+ * purpose with or without fee is hereby granted.                           *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
+ ****************************************************************************/
+
+/**
+ * Date/time handling.
+ */
+
+#ifndef BFS_TIME_H
+#define BFS_TIME_H
+
+#include <time.h>
+
+/**
+ * localtime_r() wrapper that calls tzset() first.
+ *
+ * @param[in] timep
+ *         The time_t to convert.
+ * @param[out] result
+ *         Buffer to hold the result.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int xlocaltime(const time_t *timep, struct tm *result);
+
+/**
+ * gmtime_r() wrapper that calls tzset() first.
+ *
+ * @param[in] timep
+ *         The time_t to convert.
+ * @param[out] result
+ *         Buffer to hold the result.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int xgmtime(const time_t *timep, struct tm *result);
+
+/**
+ * mktime() wrapper that reports errors more reliably.
+ *
+ * @param[in,out] tm
+ *         The struct tm to convert.
+ * @param[out] timep
+ *         A pointer to the result.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int xmktime(struct tm *tm, time_t *timep);
+
+/**
+ * A portable timegm(), the inverse of gmtime().
+ *
+ * @param[in,out] tm
+ *         The struct tm to convert.
+ * @param[out] timep
+ *         A pointer to the result.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int xtimegm(struct tm *tm, time_t *timep);
+
+/**
+ * Parse an ISO 8601-style timestamp.
+ *
+ * @param[in] str
+ *         The string to parse.
+ * @param[out] result
+ *         A pointer to the result.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int parse_timestamp(const char *str, struct timespec *result);
+
+#endif // BFS_TIME_H
diff --git a/util.c b/util.c
index 6af7d27..ec019ce 100644
--- a/util.c
+++ b/util.c
@@ -163,92 +163,6 @@ char *xregerror(int err, const regex_t *regex) {
 	return str;
 }
 
-int xlocaltime(const time_t *timep, struct tm *result) {
-	// Should be called before localtime_r() according to POSIX.1-2004
-	tzset();
-
-	if (localtime_r(timep, result)) {
-		return 0;
-	} else {
-		return -1;
-	}
-}
-
-int xgmtime(const time_t *timep, struct tm *result) {
-	// Should be called before gmtime_r() according to POSIX.1-2004
-	tzset();
-
-	if (gmtime_r(timep, result)) {
-		return 0;
-	} else {
-		return -1;
-	}
-}
-
-int xmktime(struct tm *tm, time_t *timep) {
-	*timep = mktime(tm);
-
-	if (*timep == -1) {
-		int error = errno;
-
-		struct tm tmp;
-		if (xlocaltime(timep, &tmp) != 0) {
-			return -1;
-		}
-
-		if (tm->tm_year != tmp.tm_year || tm->tm_yday != tmp.tm_yday
-		    || tm->tm_hour != tmp.tm_hour || tm->tm_min != tmp.tm_min || tm->tm_sec != tmp.tm_sec) {
-			errno = error;
-			return -1;
-		}
-	}
-
-	return 0;
-}
-
-int xtimegm(struct tm *tm, time_t *timep) {
-	// Some man pages for timegm() recommend this as a portable approach
-	int ret = -1;
-	int error;
-
-	char *old_tz = getenv("TZ");
-	if (old_tz) {
-		old_tz = strdup(old_tz);
-		if (!old_tz) {
-			error = errno;
-			goto fail;
-		}
-	}
-
-	if (setenv("TZ", "UTC0", true) != 0) {
-		error = errno;
-		goto fail;
-	}
-
-	ret = xmktime(tm, timep);
-	error = errno;
-
-	if (old_tz) {
-		if (setenv("TZ", old_tz, true) != 0) {
-			ret = -1;
-			error = errno;
-			goto fail;
-		}
-	} else {
-		if (unsetenv("TZ") != 0) {
-			ret = -1;
-			error = errno;
-			goto fail;
-		}
-	}
-
-	tzset();
-fail:
-	free(old_tz);
-	errno = error;
-	return ret;
-}
-
 void format_mode(mode_t mode, char str[11]) {
 	strcpy(str, "----------");
 
diff --git a/util.h b/util.h
index ae12703..6e7c1f2 100644
--- a/util.h
+++ b/util.h
@@ -27,7 +27,6 @@
 #include <regex.h>
 #include <stdbool.h>
 #include <sys/types.h>
-#include <time.h>
 
 // Some portability concerns
 
@@ -160,52 +159,6 @@ int pipe_cloexec(int pipefd[2]);
 char *xregerror(int err, const regex_t *regex);
 
 /**
- * localtime_r() wrapper that calls tzset() first.
- *
- * @param timep
- *         The time_t to convert.
- * @param result
- *         Buffer to hold the result.
- * @return 0 on success, -1 on failure.
- */
-int xlocaltime(const time_t *timep, struct tm *result);
-
-/**
- * gmtime_r() wrapper that calls tzset() first.
- *
- * @param timep
- *         The time_t to convert.
- * @param result
- *         Buffer to hold the result.
- * @return 0 on success, -1 on failure.
- */
-int xgmtime(const time_t *timep, struct tm *result);
-
-/**
- * mktime() wrapper that reports errors more reliably.
- *
- * @param[in,out] tm
- *         The struct tm to convert.
- * @param[out] timep
- *         Where to store the result.
- * @return
- *         0 on success, -1 on failure.
- */
-int xmktime(struct tm *tm, time_t *timep);
-
-/**
- * A portable timegm(), the inverse of gmtime().
- *
- * @param[in,out] tm
- *         The struct tm to convert.
- * @param[out] timep
- *         Where to store the result.
- * @return
- *         0 on success, -1 on failure.
- */
-int xtimegm(struct tm *tm, time_t *timep);
-
-/**
  * Format a mode like ls -l (e.g. -rw-r--r--).
  *
  * @param mode