log: make more logging options configurable

* Add --log-colorize=never|always|auto
* Add --log-no-syslog

completions/zsh/_yambar

@@ -7,4 +7,6 @@ _arguments \
     '(-b --backend)'{-b,--backend}'[backend to use (default: auto)]:backend:(xcb wayland auto)' \
     '(-c --config)'{-c,--config}'[alternative configuration file]:filename:_files' \
     '(-C --validate)'{-C,--validate}'[verify configuration then quit]' \
-    '(-p --print-pid)'{-p,--print-pid}'[print PID to this file or FD when up and running]:pidfile:_files'
+    '(-p --print-pid)'{-p,--print-pid}'[print PID to this file or FD when up and running]:pidfile:_files' \
+    '(-l --log-colorize)'{-l,--log-colorize}'[enable or disable colorization of log output on stderr]:logcolor:(never always auto)' \
+    '(-s --log-no-syslog)'{-s,--log-no-syslog}'[disable syslog logging]'

doc/yambar.1.scd

@@ -27,6 +27,12 @@ yambar - modular status panel for X11 and Wayland
 	(or FD) is closed immediately after writing the PID. When a _FILE_
 	as been specified, the file is unlinked when yambar exits.
 
+*-l*,*--log-colorize*=[{*never*,*always*,*auto*}]
+	Enables or disables colorization of log output on stderr.
+
+*-s*,*--log-no-syslog*
+	Disables syslog logging. Logging is only done on stderr.
+
 *-v*,*--version*
 	Show the version number and quit
 

log.c

@@ -12,18 +12,24 @@
 #include <syslog.h>
 
 static bool colorize = false;
+static bool do_syslog = true;
 
-static void __attribute__((constructor))
+void
-init(void)
+log_init(enum log_colorize _colorize, bool _do_syslog)
 {
-    colorize = isatty(STDERR_FILENO);
+    colorize = _colorize == LOG_COLORIZE_NEVER ? false : _colorize == LOG_COLORIZE_ALWAYS ? true : isatty(STDERR_FILENO);
+    do_syslog = _do_syslog;
+
+    if (do_syslog) {
         openlog(NULL, /*LOG_PID*/0, LOG_USER);
         setlogmask(LOG_UPTO(LOG_WARNING));
     }
+}
 
-static void __attribute__((destructor))
+void
-fini(void)
+log_deinit(void)
 {
+    if (do_syslog)
         closelog();
 }
 
@@ -66,6 +72,9 @@ static void
 _sys_log(enum log_class log_class, const char *module, const char *file,
          int lineno, const char *fmt, int sys_errno, va_list va)
 {
+    if (!do_syslog)
+        return;
+
     /* Map our log level to syslog's level */
     int level = -1;
     switch (log_class) {
@@ -85,7 +94,8 @@ _sys_log(enum log_class log_class, const char *module, const char *file,
     /* Calculate required size of buffer holding the entire log message */
     int required_len = 0;
     required_len += strlen(module) + 2;  /* "%s: " */
-    required_len += vsnprintf(NULL, 0, fmt, va2); va_end(va2);
+    required_len += vsnprintf(NULL, 0, fmt, va2);
+    va_end(va2);
 
     if (sys_errno != 0)
         required_len += strlen(sys_err) + 2; /* ": %s" */

log.h

@@ -1,7 +1,13 @@
 #pragma once
 
+#include <stdbool.h>
+
+enum log_colorize { LOG_COLORIZE_NEVER, LOG_COLORIZE_ALWAYS, LOG_COLORIZE_AUTO };
 enum log_class { LOG_CLASS_ERROR, LOG_CLASS_WARNING, LOG_CLASS_INFO, LOG_CLASS_DEBUG };
 
+void log_init(enum log_colorize colorize, bool do_syslog);
+void log_deinit(void);
+
 void log_msg(enum log_class log_class, const char *module,
                const char *file, int lineno,
                const char *fmt, ...) __attribute__((format (printf, 5, 6)));

main.c

@@ -131,7 +131,9 @@ print_usage(const char *prog_name)
            "  -c,--config=FILE                      alternative configuration file\n"
            "  -C,--validate                         verify configuration then quit\n"
            "  -p,--print-pid=FILE|FD                print PID to file or FD\n"
-           "  -v,--version                     print f00sel version and quit\n");
+           "  -l,--log-colorize=[never|always|auto] enable/disable colorization of log output on stderr\n"
+           "  -s,--log-no-syslog                    disable syslog logging\n"
+           "  -v,--version                          show the version number and quit\n");
 }
 
 static bool
@@ -181,6 +183,8 @@ main(int argc, char *const *argv)
         {"config",           required_argument, 0, 'c'},
         {"validate",         no_argument,       0, 'C'},
         {"print-pid",        required_argument, 0, 'p'},
+        {"log-colorize",     optional_argument, 0, 'l'},
+        {"log-no-syslog",    no_argument,       0, 's'},
         {"version",          no_argument,       0, 'v'},
         {"help",             no_argument,       0, 'h'},
         {NULL,               no_argument,       0, 0},
@@ -193,8 +197,11 @@ main(int argc, char *const *argv)
     char *config_path = NULL;
     enum bar_backend backend = BAR_BACKEND_AUTO;
 
+    enum log_colorize log_colorize = LOG_COLORIZE_AUTO;
+    bool log_syslog = true;
+
     while (true) {
-        int c = getopt_long(argc, argv, ":b:c:Cp:vh", longopts, NULL);
+        int c = getopt_long(argc, argv, ":b:c:Cp:l::svh", longopts, NULL);
         if (c == -1)
             break;
 
@@ -205,7 +212,7 @@ main(int argc, char *const *argv)
             else if (strcmp(optarg, "wayland") == 0)
                 backend = BAR_BACKEND_WAYLAND;
             else {
-                LOG_ERR("%s: invalid backend", optarg);
+                fprintf(stderr, "%s: invalid backend\n", optarg);
                 return EXIT_FAILURE;
             }
             break;
@@ -213,10 +220,10 @@ main(int argc, char *const *argv)
         case 'c': {
             struct stat st;
             if (stat(optarg, &st) == -1) {
-                LOG_ERRNO("%s: invalid configuration file", optarg);
+                fprintf(stderr, "%s: invalid configuration file: %s\n", optarg, strerror(errno));
                 return EXIT_FAILURE;
             } else if (!S_ISREG(st.st_mode)) {
-                LOG_ERR("%s: invalid configuration file: not a regular file",
+                fprintf(stderr, "%s: invalid configuration file: not a regular file\n",
                         optarg);
                 return EXIT_FAILURE;
             }
@@ -233,6 +240,23 @@ main(int argc, char *const *argv)
             pid_file = optarg;
             break;
 
+        case 'l':
+            if (optarg == NULL || strcmp(optarg, "auto") == 0)
+                log_colorize = LOG_COLORIZE_AUTO;
+            else if (strcmp(optarg, "never") == 0)
+                log_colorize = LOG_COLORIZE_NEVER;
+            else if (strcmp(optarg, "always") == 0)
+                log_colorize = LOG_COLORIZE_ALWAYS;
+            else {
+                fprintf(stderr, "%s: argument must be one of 'never', 'always' or 'auto'\n", optarg);
+                return EXIT_FAILURE;
+            }
+            break;
+
+        case 's':
+            log_syslog = false;
+            break;
+
         case 'v':
             printf("yambar version %s\n", YAMBAR_VERSION);
             return EXIT_SUCCESS;
@@ -251,6 +275,8 @@ main(int argc, char *const *argv)
         }
     }
 
+    log_init(log_colorize, log_syslog);
+
     const struct sigaction sa = {.sa_handler = &signal_handler};
     sigaction(SIGINT, &sa, NULL);
     sigaction(SIGTERM, &sa, NULL);
@@ -266,6 +292,7 @@ main(int argc, char *const *argv)
     int abort_fd = eventfd(0, EFD_CLOEXEC);
     if (abort_fd == -1) {
         LOG_ERRNO("failed to create eventfd (for abort signalling)");
+        log_deinit();
         return 1;
     }
 
@@ -273,6 +300,7 @@ main(int argc, char *const *argv)
         config_path = get_config_path();
         if (config_path == NULL) {
             LOG_ERR("could not find a configuration (see man 5 yambar)");
+            log_deinit();
             return 1;
         }
     }
@@ -282,12 +310,14 @@ main(int argc, char *const *argv)
 
     if (bar == NULL) {
         close(abort_fd);
+        log_deinit();
         return 1;
     }
 
     if (verify_config) {
         bar->destroy(bar);
         close(abort_fd);
+        log_deinit();
         return 0;
     }
 
@@ -335,5 +365,6 @@ done:
 
     if (unlink_pid_file)
         unlink(pid_file);
+    log_deinit();
     return res;
 }