Log to /var/log/apk.log

This adds a log file at /var/log/apk.log. On each run, apk's version
information and the current date & time are written to this file,
followed by any normal apk output.

doc/apk.8.scd

@@ -15,6 +15,8 @@ to install is called the _world_ (see *apk-world*(5)). *apk* supports various
 sub-commands to query and manipulate _world_ and local & remote package
 repositories.
 
+All apk commands which modify the database are logged to /var/log/apk.log.
+
 # COMMANDS
 
 Each command is documented in detail on its manual page.

src/apk.c

@@ -46,11 +46,11 @@ time_t time(time_t *tloc)
 }
 #endif
 
-static void version(struct apk_out *out)
+static void version(struct apk_out *out, const char *prefix)
 {
-	apk_out(out, "apk-tools " APK_VERSION ", compiled for " APK_DEFAULT_ARCH ".");
+	apk_out_fmt(out, prefix, "apk-tools " APK_VERSION ", compiled for " APK_DEFAULT_ARCH ".");
 #ifdef TEST_MODE
-	apk_out(out, "TEST MODE BUILD. NOT FOR PRODUCTION USE.");
+	apk_out_fmt(out, prefix, "TEST MODE BUILD. NOT FOR PRODUCTION USE.");
 #endif
 }
 
@@ -122,7 +122,7 @@ static int option_parse_global(void *ctx, struct apk_ctx *ac, int opt, const cha
 		ac->out.verbosity++;
 		break;
 	case OPT_GLOBAL_version:
-		version(out);
+		version(out, NULL);
 		return -ESHUTDOWN;
 	case OPT_GLOBAL_force:
 		ac->force |= APK_FORCE_OVERWRITE | APK_FORCE_OLD_APK
@@ -260,7 +260,7 @@ const struct apk_option_group optgroup_commit = {
 
 static int usage(struct apk_out *out, struct apk_applet *applet)
 {
-	version(out);
+	version(out, NULL);
 	apk_applet_help(applet, out);
 	return 1;
 }
@@ -460,6 +460,9 @@ int main(int argc, char **argv)
 	r = apk_ctx_prepare(&ctx);
 	if (r != 0) goto err;
 
+	apk_out_log_argv(&ctx.out, apk_argv);
+	version(&ctx.out, APK_OUT_LOG_ONLY);
+
 	if (ctx.open_flags) {
 		r = apk_db_open(&db, &ctx);
 		if (r != 0) {

src/apk_print.h

@@ -30,11 +30,15 @@ void apk_url_parse(struct apk_url_print *, const char *);
 struct apk_out {
 	int verbosity;
 	unsigned int width, last_change;
-	FILE *out, *err;
+	FILE *out, *err, *log;
 };
 
 static inline int apk_out_verbosity(struct apk_out *out) { return out->verbosity; }
 
+// Pass this as the prefix to skip logging to the console (but still write to
+// the log file).
+#define APK_OUT_LOG_ONLY ((const char*)-1)
+
 #define apk_err(out, args...)	do { apk_out_fmt(out, "ERROR: ", args); } while (0)
 #define apk_out(out, args...)	do { apk_out_fmt(out, NULL, args); } while (0)
 #define apk_warn(out, args...)	do { if (apk_out_verbosity(out) >= 0) { apk_out_fmt(out, "WARNING: ", args); } } while (0)
@@ -44,6 +48,7 @@ static inline int apk_out_verbosity(struct apk_out *out) { return out->verbosity
 
 void apk_out_reset(struct apk_out *);
 void apk_out_fmt(struct apk_out *, const char *prefix, const char *format, ...);
+void apk_out_log_argv(struct apk_out *, char **argv);
 
 struct apk_progress {
 	struct apk_out *out;

src/context.c

@@ -29,6 +29,7 @@ void apk_ctx_free(struct apk_ctx *ac)
 	apk_trust_free(&ac->trust);
 	apk_string_array_free(&ac->repository_list);
 	apk_string_array_free(&ac->private_keys);
+	if (ac->out.log) fclose(ac->out.log);
 }
 
 int apk_ctx_prepare(struct apk_ctx *ac)
@@ -53,6 +54,21 @@ int apk_ctx_prepare(struct apk_ctx *ac)
 		apk_err(&ac->out, "Unable to open root: %s", apk_error_str(errno));
 		return -errno;
 	}
+
+	if (ac->open_flags & APK_OPENF_WRITE) {
+		const char *log_path = "var/log/apk.log", *log_dir = "var/log";
+		const int lflags = O_WRONLY | O_APPEND | O_CREAT | O_CLOEXEC;
+		int fd = openat(ac->root_fd, log_path, lflags, 0644);
+		if (fd < 0 && (ac->open_flags & APK_OPENF_CREATE)) {
+			mkdirat(ac->root_fd, log_dir, 0755);
+			fd = openat(ac->root_fd, log_path, lflags, 0644);
+		}
+		if (fd < 0) {
+			apk_err(&ac->out, "Unable to open log: %s", apk_error_str(errno));
+			return -errno;
+		}
+		ac->out.log = fdopen(fd, "a");
+	}
 	return 0;
 }
 

src/print.c

@@ -136,10 +136,35 @@ static void log_internal(FILE *dest, const char *prefix, const char *format, va_
 void apk_out_fmt(struct apk_out *out, const char *prefix, const char *format, ...)
 {
 	va_list va;
+	if (prefix != APK_OUT_LOG_ONLY) {
 		va_start(va, format);
 		log_internal(prefix ? out->err : out->out, prefix, format, va);
 		out->last_change++;
 		va_end(va);
+	}
+
+	if (out->log) {
+		va_start(va, format);
+		log_internal(out->log, prefix, format, va);
+		va_end(va);
+	}
+}
+
+void apk_out_log_argv(struct apk_out *out, char **argv)
+{
+	char when[32];
+	struct tm tm;
+	time_t now = time(NULL);
+
+	if (!out->log) return;
+	fprintf(out->log, "\nRunning `");
+	for (int i = 0; argv[i]; ++i) {
+		fprintf(out->log, "%s%s", argv[i], argv[i+1] ? " " : "");
+	}
+
+	gmtime_r(&now, &tm);
+	strftime(when, sizeof(when), "%Y-%m-%d %H:%M:%S", &tm);
+	fprintf(out->log, "` at %s\n", when);
 }
 
 void apk_print_progress(struct apk_progress *p, size_t done, size_t total)