all repos — slstatus @ 80fc20d1d69b14f36ad9bb64d8af38481cbf1ff5

my build of slstatus (tools.suckless.org/slstatus/) 

Add warn() and die()

Given slstatus is a tool that runs in the background, most likely run
from .xinitrc, it's important to prepend the name of the tool to error
messages so it becomes clear where the error is coming from.

To make this much more consistent, this commit adds warn() and die()
utility functions consistent with other suckless projects and adapts all
calls to fprintf(stderr, *) to the warn() and die() functions, greatly
increasing the readability of the code.
Laslo Hunhold dev@frign.de
Fri, 18 May 2018 10:59:05 +0200
commit

80fc20d1d69b14f36ad9bb64d8af38481cbf1ff5

parent

a4fe8c97414f07dd8b891e0d325dd2733195151d

20 files changed, 99 insertions(+), 76 deletions(-)

jump to
M components/battery.c → components/battery.c 
@@ -59,13 +59,12 @@ int fd;
 
 		fd = open("/dev/apm", O_RDONLY);
 		if (fd < 0) {
-			fprintf(stderr, "open '/dev/apm': %s\n", strerror(errno));
+			warn("open '/dev/apm':");
 			return NULL;
 		}
 
 		if (ioctl(fd, APM_IOC_GETPOWER, &apm_info) < 0) {
-			fprintf(stderr, "ioctl 'APM_IOC_GETPOWER': %s\n",
-			        strerror(errno));
+			warn("ioctl 'APM_IOC_GETPOWER':");
 			close(fd);
 			return NULL;
 		}

@@ -90,13 +89,12 @@ };
 
 		fd = open("/dev/apm", O_RDONLY);
 		if (fd < 0) {
-			fprintf(stderr, "open '/dev/apm': %s\n", strerror(errno));
+			warn("open '/dev/apm':");
 			return NULL;
 		}
 
 		if (ioctl(fd, APM_IOC_GETPOWER, &apm_info) < 0) {
-			fprintf(stderr, "ioctl 'APM_IOC_GETPOWER': %s\n",
-			        strerror(errno));
+			warn("ioctl 'APM_IOC_GETPOWER':");
 			close(fd);
 			return NULL;
 		}
M components/cpu.c → components/cpu.c 
@@ -57,7 +57,7 @@ 
 		size = sizeof(freq);
 
 		if (sysctl(mib, 2, &freq, &size, NULL, 0) < 0) {
-			fprintf(stderr, "sysctl 'HW_CPUSPEED': %s\n", strerror(errno));
+			warn("sysctl 'HW_CPUSPEED':");
 			return NULL;
 		}
 

@@ -80,7 +80,7 @@ size = sizeof(a);
 
 		memcpy(b, a, sizeof(b));
 		if (sysctl(mib, 2, &a, &size, NULL, 0) < 0) {
-			fprintf(stderr, "sysctl 'KERN_CPTIME': %s\n", strerror(errno));
+			warn("sysctl 'KERN_CPTIME':");
 			return NULL;
 		}
 		if (!valid) {
M components/datetime.c → components/datetime.c 
@@ -11,7 +11,7 @@ time_t t;
 
 	t = time(NULL);
 	if (!strftime(buf, sizeof(buf), fmt, localtime(&t))) {
-		fprintf(stderr, "strftime: Result string exceeds buffer size\n");
+		warn("strftime: Result string exceeds buffer size");
 		return NULL;
 	}
M components/disk.c → components/disk.c 
@@ -12,7 +12,7 @@ {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
-		fprintf(stderr, "statvfs '%s': %s\n", mnt, strerror(errno));
+		warn("statvfs '%s':", mnt);
 		return NULL;
 	}
 

@@ -26,7 +26,7 @@ {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
-		fprintf(stderr, "statvfs '%s': %s\n", mnt, strerror(errno));
+		warn("statvfs '%s':", mnt);
 		return NULL;
 	}
 

@@ -40,7 +40,7 @@ {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
-		fprintf(stderr, "statvfs '%s': %s\n", mnt, strerror(errno));
+		warn("statvfs '%s':", mnt);
 		return NULL;
 	}
 

@@ -54,7 +54,7 @@ {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
-		fprintf(stderr, "statvfs '%s': %s\n", mnt, strerror(errno));
+		warn("statvfs '%s':", mnt);
 		return NULL;
 	}
M components/hostname.c → components/hostname.c 
@@ -10,7 +10,7 @@ const char *
 hostname(void)
 {
 	if (gethostname(buf, sizeof(buf)) < 0) {
-		fprintf(stderr, "gethostbyname: %s\n", strerror(errno));
+		warn("gethostbyname:");
 		return NULL;
 	}
M components/ip.c → components/ip.c 
@@ -19,7 +19,7 @@ int s;
 	char host[NI_MAXHOST];
 
 	if (getifaddrs(&ifaddr) < 0) {
-		fprintf(stderr, "getifaddrs: %s\n", strerror(errno));
+		warn("getifaddrs:");
 		return NULL;
 	}
 

@@ -32,7 +32,7 @@ NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
 		if (!strcmp(ifa->ifa_name, iface) &&
 		    (ifa->ifa_addr->sa_family == AF_INET)) {
 			if (s != 0) {
-				fprintf(stderr, "getnameinfo: %s\n", gai_strerror(s));
+				warn("getnameinfo: %s", gai_strerror(s));
 				return NULL;
 			}
 			return bprintf("%s", host);

@@ -52,7 +52,7 @@ int s;
 	char host[NI_MAXHOST];
 
 	if (getifaddrs(&ifaddr) < 0) {
-		fprintf(stderr, "getifaddrs: %s\n", strerror(errno));
+		warn("getifaddrs:");
 		return NULL;
 	}
 

@@ -65,7 +65,7 @@ NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
 		if (!strcmp(ifa->ifa_name, iface) &&
 		    (ifa->ifa_addr->sa_family == AF_INET6)) {
 			if (s != 0) {
-				fprintf(stderr, "getnameinfo: %s\n", gai_strerror(s));
+				warn("getnameinfo: %s", gai_strerror(s));
 				return NULL;
 			}
 			return bprintf("%s", host);
M components/kernel_release.c → components/kernel_release.c 
@@ -12,7 +12,7 @@ {
 	struct utsname udata;
 
 	if (uname(&udata) < 0) {
-		fprintf(stderr, "uname: %s\n", strerror(errno));
+		warn("uname:");
 		return NULL;
 	}
M components/keyboard_indicators.c → components/keyboard_indicators.c 
@@ -11,7 +11,7 @@ Display *dpy;
 	XKeyboardState state;
 
 	if (!(dpy = XOpenDisplay(NULL))) {
-		fprintf(stderr, "Cannot open display\n");
+		warn("XOpenDisplay: Failed to open display");
 		return NULL;
 	}
 	XGetKeyboardControl(dpy, &state);
M components/load_avg.c → components/load_avg.c 
@@ -10,7 +10,7 @@ {
 	double avgs[3];
 
 	if (getloadavg(avgs, 3) < 0) {
-		fprintf(stderr, "getloadavg: Could not obtain load average.\n");
+		warn("getloadavg: Failed to obtain load average");
 		return NULL;
 	}
M components/num_files.c → components/num_files.c 
@@ -14,7 +14,7 @@ DIR *fd;
 	int num;
 
 	if (!(fd = opendir(dir))) {
-		fprintf(stderr, "opendir '%s': %s\n", dir, strerror(errno));
+		warn("opendir '%s':", dir);
 		return NULL;
 	}
M components/run_command.c → components/run_command.c 
@@ -12,7 +12,7 @@ char *p;
 	FILE *fp;
 
 	if (!(fp = popen(cmd, "r"))) {
-		fprintf(stderr, "popen '%s': %s\n", cmd, strerror(errno));
+		warn("popen '%s':", cmd);
 		return NULL;
 	}
 	p = fgets(buf, sizeof(buf) - 1, fp);
M components/swap.c → components/swap.c 
@@ -13,11 +13,11 @@ FILE *fp;
 		size_t bytes_read;
 
 		if (!(fp = fopen(path, "r"))) {
-			fprintf(stderr, "fopen '%s': %s\n", path, strerror(errno));
+			warn("fopen '%s':", path);
 			return 0;
 		}
 		if (!(bytes_read = fread(buf, sizeof(char), bufsiz, fp))) {
-			fprintf(stderr, "fread '%s': %s\n", path, strerror(errno));
+			warn("fread '%s':", path);
 			fclose(fp);
 			return 0;
 		}

@@ -139,21 +139,21 @@ int rnswap, nswap, i;
 
 		nswap = swapctl(SWAP_NSWAP, 0, 0);
 		if (nswap < 1) {
-			fprintf(stderr, "swaptctl 'SWAP_NSWAP': %s\n", strerror(errno));
+			warn("swaptctl 'SWAP_NSWAP':");
 		}
 
 		fsep = sep = calloc(nswap, sizeof(*sep));
 		if (!sep) {
-			fprintf(stderr, "calloc 'nswap': %s\n", strerror(errno));
+			warn("calloc 'nswap':");
 		}
 
 		rnswap = swapctl(SWAP_STATS, (void *)sep, nswap);
 		if (rnswap < 0) {
-			fprintf(stderr, "swapctl 'SWAP_STATA': %s\n", strerror(errno));
+			warn("swapctl 'SWAP_STATA':");
 		}
 
 		if (nswap != rnswap) {
-			fprintf(stderr, "SWAP_STATS != SWAP_NSWAP\n");
+			warn("getstats: SWAP_STATS != SWAP_NSWAP");
 		}
 
 		*total = 0;
M components/temperature.c → components/temperature.c 
@@ -36,8 +36,7 @@ 
 		size = sizeof(temp);
 
 		if (sysctl(mib, 5, &temp, &size, NULL, 0) < 0) {
-			fprintf(stderr, "sysctl 'SENSOR_TEMP': %s\n",
-			        strerror(errno));
+			warn("sysctl 'SENSOR_TEMP':");
 			return NULL;
 		}
M components/uptime.c → components/uptime.c 
@@ -50,7 +50,7 @@ 
 		size = sizeof(boottime);
 
 		if (sysctl(mib, 2, &boottime, &size, NULL, 0) < 0) {
-			fprintf(stderr, "sysctl 'KERN_BOOTTIME': %s\n", strerror(errno));
+			warn("sysctl 'KERN_BOOTTIME':");
 			return NULL;
 		}
M components/user.c → components/user.c 
@@ -20,7 +20,7 @@ {
 	struct passwd *pw;
 
 	if (!(pw = getpwuid(geteuid()))) {
-		fprintf(stderr, "getpwuid '%d': %s\n", geteuid(), strerror(errno));
+		warn("getpwuid '%d':", geteuid());
 		return NULL;
 	}
M components/volume.c → components/volume.c 
@@ -21,21 +21,19 @@ int v, afd, devmask;
 	char *vnames[] = SOUND_DEVICE_NAMES;
 
 	if ((afd = open(card, O_RDONLY | O_NONBLOCK)) < 0) {
-		fprintf(stderr, "open '%s': %s\n", card, strerror(errno));
+		warn("open '%s':", card);
 		return NULL;
 	}
 
 	if (ioctl(afd, (int)SOUND_MIXER_READ_DEVMASK, &devmask) < 0) {
-		fprintf(stderr, "ioctl 'SOUND_MIXER_READ_DEVMASK': %s\n",
-		        strerror(errno));
+		warn("ioctl 'SOUND_MIXER_READ_DEVMASK':");
 		close(afd);
 		return NULL;
 	}
 	for (i = 0; i < LEN(vnames); i++) {
 		if (devmask & (1 << i) && !strcmp("vol", vnames[i])) {
 			if (ioctl(afd, MIXER_READ(i), &v) < 0) {
-				fprintf(stderr, "ioctl 'MIXER_READ(%ld)': %s\n", i,
-				        strerror(errno));
+				warn("ioctl 'MIXER_READ(%ld)':", i);
 				close(afd);
 				return NULL;
 			}
M components/wifi.c → components/wifi.c 
@@ -26,8 +26,7 @@ 
 		snprintf(path, sizeof(path), "%s%s%s", "/sys/class/net/", iface,
 		         "/operstate");
 		if (!(fp = fopen(path, "r"))) {
-			fprintf(stderr, "fopen '%s': %s\n", path,
-			        strerror(errno));
+			warn("fopen '%s':", path);
 			return NULL;
 		}
 		p = fgets(status, 5, fp);

@@ -37,8 +36,7 @@ return NULL;
 		}
 
 		if (!(fp = fopen("/proc/net/wireless", "r"))) {
-			fprintf(stderr, "fopen '/proc/net/wireless': %s\n",
-			        strerror(errno));
+			warn("fopen '/proc/net/wireless':");
 			return NULL;
 		}
 

@@ -74,13 +72,12 @@ wreq.u.essid.length = IW_ESSID_MAX_SIZE+1;
 		snprintf(wreq.ifr_name, sizeof(wreq.ifr_name), "%s", iface);
 
 		if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-			fprintf(stderr, "socket 'AF_INET': %s\n",
-			        strerror(errno));
+			warn("socket 'AF_INET':");
 			return NULL;
 		}
 		wreq.u.essid.pointer = id;
 		if (ioctl(sockfd,SIOCGIWESSID, &wreq) < 0) {
-			fprintf(stderr, "ioctl 'SIOCGIWESSID': %s\n", strerror(errno));
+			warn("ioctl 'SIOCGIWESSID':");
 			close(sockfd);
 			return NULL;
 		}

@@ -111,22 +108,19 @@ 
 		memset(&bssid, 0, sizeof(bssid));
 		memset(nr, 0, sizeof(struct ieee80211_nodereq));
 		if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-			fprintf(stderr, "socket 'AF_INET': %s\n",
-				strerror(errno));
+			warn("socket 'AF_INET':");
 			return 0;
 		}
 		strlcpy(bssid.i_name, iface, sizeof(bssid.i_name));
 		if ((ioctl(sockfd, SIOCG80211BSSID, &bssid)) < 0) {
-			fprintf(stderr, "ioctl 'SIOCG80211BSSID': %s\n",
-				strerror(errno));
+			warn("ioctl 'SIOCG80211BSSID':");
 			close(sockfd);
 			return 0;
 		}
 		strlcpy(nr->nr_ifname, iface, sizeof(nr->nr_ifname));
 		memcpy(&nr->nr_macaddr, bssid.i_bssid, sizeof(nr->nr_macaddr));
 		if ((ioctl(sockfd, SIOCG80211NODE, nr)) < 0 && nr->nr_rssi) {
-			fprintf(stderr, "ioctl 'SIOCG80211NODE': %s\n",
-				strerror(errno));
+			warn("ioctl 'SIOCG80211NODE':");
 			close(sockfd);
 			return 0;
 		}
M slstatus.c → slstatus.c 
@@ -17,7 +17,6 @@ const char *fmt;
 	const char *args;
 };
 
-char *argv0;
 char buf[1024];
 static int done;
 static Display *dpy;

@@ -43,8 +42,7 @@ 
 static void
 usage(void)
 {
-	fprintf(stderr, "usage: %s [-s]\n", argv0);
-	exit(1);
+	die("usage: %s [-s]", argv0);
 }
 
 int

@@ -80,14 +78,12 @@ setbuf(stdout, NULL);
 	}
 
 	if (!sflag && !(dpy = XOpenDisplay(NULL))) {
-		fprintf(stderr, "XOpenDisplay: Failed to open display\n");
-		return 1;
+		die("XOpenDisplay: Failed to open display");
 	}
 
 	while (!done) {
 		if (clock_gettime(CLOCK_MONOTONIC, &start) < 0) {
-			fprintf(stderr, "clock_gettime: %s\n", strerror(errno));
-			return 1;
+			die("clock_gettime:");
 		}
 
 		status[0] = '\0';

@@ -97,11 +93,10 @@ res = unknown_str;
 			}
 			if ((ret = snprintf(status + len, sizeof(status) - len,
 			                    args[i].fmt, res)) < 0) {
-				fprintf(stderr, "snprintf: %s\n",
-				        strerror(errno));
+				warn("snprintf:");
 				break;
 			} else if ((size_t)ret >= sizeof(status) - len) {
-				fprintf(stderr, "snprintf: Output truncated\n");
+				warn("snprintf: Output truncated");
 				break;
 			}
 			len += ret;

@@ -111,18 +106,14 @@ if (sflag) {
 			printf("%s\n", status);
 		} else {
 			if (XStoreName(dpy, DefaultRootWindow(dpy), status) < 0) {
-				fprintf(stderr,
-				        "XStoreName: Allocation failed\n");
-				return 1;
+				die("XStoreName: Allocation failed");
 			}
 			XFlush(dpy);
 		}
 
 		if (!done) {
 			if (clock_gettime(CLOCK_MONOTONIC, &current) < 0) {
-				fprintf(stderr, "clock_gettime: %s\n",
-				        strerror(errno));
-				return 1;
+				die("clock_gettime:");
 			}
 			difftimespec(&diff, &current, &start);
 

@@ -133,9 +124,7 @@ 
 			if (wait.tv_sec >= 0) {
 				if (nanosleep(&wait, NULL) < 0 &&
 				    errno != EINTR) {
-					fprintf(stderr, "nanosleep: %s\n",
-					        strerror(errno));
-					return 1;
+					die("nanosleep:");
 				}
 			}
 		}

@@ -144,9 +133,7 @@ 
 	if (!sflag) {
 		XStoreName(dpy, DefaultRootWindow(dpy), NULL);
 		if (XCloseDisplay(dpy) < 0) {
-			fprintf(stderr,
-			        "XCloseDisplay: Failed to close display\n");
-			return 1;
+			die("XCloseDisplay: Failed to close display");
 		}
 	}
M util.c → util.c 
@@ -2,10 +2,52 @@ /* See LICENSE file for copyright and license details. */
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "util.h"
 
+char *argv0;
+
+static void
+verr(const char *fmt, va_list ap)
+{
+	if (argv0 && strncmp(fmt, "usage", sizeof("usage") - 1)) {
+		fprintf(stderr, "%s: ", argv0);
+	}
+
+	vfprintf(stderr, fmt, ap);
+
+	if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
+		fputc(' ', stderr);
+		perror(NULL);
+	} else {
+		fputc('\n', stderr);
+	}
+}
+
+void
+warn(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	verr(fmt, ap);
+	va_end(ap);
+}
+
+void
+die(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	verr(fmt, ap);
+	va_end(ap);
+
+	exit(1);
+}
+
 const char *
 bprintf(const char *fmt, ...)
 {

@@ -14,9 +56,9 @@ int ret;
 
 	va_start(ap, fmt);
 	if ((ret = vsnprintf(buf, sizeof(buf), fmt, ap)) < 0) {
-		fprintf(stderr, "vsnprintf: %s\n", strerror(errno));
+		warn("vsnprintf:");
 	} else if ((size_t)ret >= sizeof(buf)) {
-		fprintf(stderr, "vsnprintf: Output truncated\n");
+		warn("vsnprintf: Output truncated");
 	}
 	va_end(ap);
 

@@ -31,7 +73,7 @@ va_list ap;
 	int n;
 
 	if (!(fp = fopen(path, "r"))) {
-		fprintf(stderr, "fopen '%s': %s\n", path, strerror(errno));
+		warn("fopen '%s':", path);
 		return -1;
 	}
 	va_start(ap, fmt);
M util.h → util.h 
@@ -3,5 +3,10 @@ extern char buf[1024];
 
 #define LEN(x) (sizeof (x) / sizeof *(x))
 
+extern char *argv0;
+
+void warn(const char *, ...);
+void die(const char *, ...);
+
 const char *bprintf(const char *fmt, ...);
 int pscanf(const char *path, const char *fmt, ...);