Add pscanf()

This reduces a lot of equivalent code to one function call.

diff --git a/slstatus.c b/slstatus.c
index cc6174a6d3558cd5b32b43db19091dba00864d6e..eb936e22f70511d7ea8ad694cc7d5d27df07fcde 100644 (file)
--- a/slstatus.c
+++ b/slstatus.c
@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <dirent.h>
 #include <err.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <ifaddrs.h>
 #include <limits.h>
@@ -93,52 +94,50 @@ bprintf(const char *fmt, ...)
        return buf;
 }
 
-static const char *
-battery_perc(const char *bat)
+int
+pscanf(const char *path, const char *fmt, ...)
 {
-       int n, perc;
-       char path[PATH_MAX];
        FILE *fp;
+       va_list ap;
+       int n;
 
-       snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/capacity");
-       fp = fopen(path, "r");
-       if (fp == NULL) {
-               warn("Failed to open file %s", path);
-               return unknown_str;
+       if (!(fp = fopen(path, "r"))) {
+               warn("fopen %s: %s\n", path, strerror(errno));
+               return -1;
        }
-       n = fscanf(fp, "%i", &perc);
+       va_start(ap, fmt);
+       n = vfscanf(fp, fmt, ap);
+       va_end(ap);
        fclose(fp);
-       if (n != 1)
-               return unknown_str;
 
-       return bprintf("%d", perc);
+       return (n == EOF) ? -1 : n;
+}
+
+static const char *
+battery_perc(const char *bat)
+{
+       int perc;
+       char path[PATH_MAX];
+
+       snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/capacity");
+       return (pscanf(path, "%i", &perc) == 1) ?
+              bprintf("%d", perc) : unknown_str;
 }
 
 static const char *
 battery_power(const char *bat)
 {
+       int watts;
        char path[PATH_MAX];
-       FILE *fp;
-       int n, watts;
 
        snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/power_now");
-       fp = fopen(path, "r");
-       if (fp == NULL) {
-               warn("Failed to open file %s", path);
-               return unknown_str;
-       }
-       n = fscanf(fp, "%i", &watts);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
-
-       return bprintf("%d", (watts + 500000) / 1000000);
+       return (pscanf(path, "%i", &watts) == 1) ?
+              bprintf("%d", (watts + 500000) / 1000000) : unknown_str;
 }
 
 static const char *
 battery_state(const char *bat)
 {
-       FILE *fp;
        struct {
                char *state;
                char *symbol;
@@ -149,81 +148,55 @@ battery_state(const char *bat)
                { "Unknown",     "/" },
        };
        size_t i;
-       int n;
        char path[PATH_MAX], state[12];
 
        snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/status");
-       fp = fopen(path, "r");
-       if (fp == NULL) {
-               warn("Failed to open file %s", path);
+       if (pscanf(path, "%12s", state) != 1) {
                return unknown_str;
        }
-       n = fscanf(fp, "%12s", state);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
 
        for (i = 0; i < LEN(map); i++) {
                if (!strcmp(map[i].state, state)) {
                        break;
                }
        }
-
        return (i == LEN(map)) ? "?" : map[i].symbol;
 }
 
 static const char *
 cpu_freq(void)
 {
-       int n, freq;
-       FILE *fp;
+       int freq;
 
-       fp = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq");
-               return unknown_str;
-       }
-       n = fscanf(fp, "%i", &freq);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
-
-       return bprintf("%d", (freq + 500) / 1000);
+       return (pscanf("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq",
+                      "%i", &freq) != 1) ?
+              bprintf("%d", (freq + 500) / 1000) : unknown_str;
 }
 
 static const char *
 cpu_perc(void)
 {
        struct timespec delay;
-       int n, perc;
+       int perc;
        long double a[4], b[4];
-       FILE *fp;
 
-       fp = fopen("/proc/stat", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/stat");
+       if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2],
+                  &a[3]) != 4) {
                return unknown_str;
        }
-       n = fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]);
-       fclose(fp);
-       if (n != 4)
-               return unknown_str;
 
        delay.tv_sec = (interval / 2) / 1000;
        delay.tv_nsec = ((interval / 2) % 1000) * 1000000;
        nanosleep(&delay, NULL);
 
-       fp = fopen("/proc/stat", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/stat");
+       if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2],
+                  &b[3]) != 4) {
                return unknown_str;
        }
-       n = fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]);
-       fclose(fp);
-       if (n != 4)
-               return unknown_str;
 
-       perc = 100 * ((b[0]+b[1]+b[2]) - (a[0]+a[1]+a[2])) / ((b[0]+b[1]+b[2]+b[3]) - (a[0]+a[1]+a[2]+a[3]));
+       perc = 100 * ((b[0]+b[1]+b[2]) - (a[0]+a[1]+a[2])) /
+              ((b[0]+b[1]+b[2]+b[3]) - (a[0]+a[1]+a[2]+a[3]));
+
        return bprintf("%d", perc);
 }
 
@@ -297,20 +270,10 @@ disk_used(const char *mnt)
 static const char *
 entropy(void)
 {
-       int n, num;
-       FILE *fp;
+       int num;
 
-       fp= fopen("/proc/sys/kernel/random/entropy_avail", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/sys/kernel/random/entropy_avail");
-               return unknown_str;
-       }
-       n = fscanf(fp, "%d", &num);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
-
-       return bprintf("%d", num);
+        return (pscanf("/proc/sys/kernel/random/entropy_avail", "%d", &num) == 1) ?
+                      bprintf("%d", num) : unknown_str;
 }
 
 static const char *
@@ -438,92 +401,48 @@ static const char *
 ram_free(void)
 {
        long free;
-       FILE *fp;
-       int n;
 
-       fp = fopen("/proc/meminfo", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/meminfo");
-               return unknown_str;
-       }
-       n = fscanf(fp, "MemFree: %ld kB\n", &free);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
-
-       return bprintf("%f", (float)free / 1024 / 1024);
+       return (pscanf("/proc/meminfo", "MemFree: %ld kB\n", &free) == 1) ?
+              bprintf("%f", (float)free / 1024 / 1024) : unknown_str;
 }
 
 static const char *
 ram_perc(void)
 {
        long total, free, buffers, cached;
-       FILE *fp;
-
-       fp = fopen("/proc/meminfo", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/meminfo");
-               return unknown_str;
-       }
-       if (fscanf(fp, "MemTotal: %ld kB\n", &total) != 1 ||
-           fscanf(fp, "MemFree: %ld kB\n", &free) != 1 ||
-           fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n",
-                  &buffers, &buffers) != 2 ||
-           fscanf(fp, "Cached: %ld kB\n", &cached) != 1)
-               goto scanerr;
-       fclose(fp);
-
-       return bprintf("%d", 100 * ((total - free) - (buffers + cached)) / total);
 
-scanerr:
-       fclose(fp);
-       return unknown_str;
+       return (pscanf("/proc/meminfo",
+                      "MemTotal: %ld kB\n"
+                      "MemFree: %ld kB\n"
+                      "MemAvailable: %ld kB\nBuffers: %ld kB\n"
+                      "Cached: %ld kB\n",
+                      &total, &free, &buffers, &buffers, &cached) == 5) ?
+              bprintf("%d", 100 * ((total - free) - (buffers + cached)) / total) :
+              unknown_str;
 }
 
 static const char *
 ram_total(void)
 {
        long total;
-       FILE *fp;
-       int n;
 
-       fp = fopen("/proc/meminfo", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/meminfo");
-               return unknown_str;
-       }
-       n = fscanf(fp, "MemTotal: %ld kB\n", &total);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
-
-       return bprintf("%f", (float)total / 1024 / 1024);
+       return (pscanf("/proc/meminfo", "MemTotal: %ld kB\n", &total) == 1) ?
+              bprintf("%f", (float)total / 1024 / 1024) : unknown_str;
 }
 
 static const char *
 ram_used(void)
 {
-       long free, total, buffers, cached;
-       FILE *fp;
-
-       fp = fopen("/proc/meminfo", "r");
-       if (fp == NULL) {
-               warn("Failed to open file /proc/meminfo");
-               return unknown_str;
-       }
-       if (fscanf(fp, "MemTotal: %ld kB\n", &total) != 1 ||
-           fscanf(fp, "MemFree: %ld kB\n", &free) != 1 ||
-           fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n",
-                  &buffers, &buffers) != 2 ||
-           fscanf(fp, "Cached: %ld kB\n", &cached) != 1)
-               goto scanerr;
-       fclose(fp);
-
-       return bprintf("%f", (float)(total - free - buffers - cached) / 1024 / 1024);
+       long total, free, buffers, cached;
 
-scanerr:
-       fclose(fp);
-       return unknown_str;
+       return (pscanf("/proc/meminfo",
+                      "MemTotal: %ld kB\n"
+                      "MemFree: %ld kB\n"
+                      "MemAvailable: %ld kB\nBuffers: %ld kB\n"
+                      "Cached: %ld kB\n",
+                      &total, &free, &buffers, &buffers, &cached) == 5) ?
+              bprintf("%f", (float)(total - free - buffers - cached) / 1024 / 1024) :
+              unknown_str;
 }
 
 static const char *
@@ -680,20 +599,10 @@ swap_used(void)
 static const char *
 temp(const char *file)
 {
-       int n, temp;
-       FILE *fp;
-
-       fp = fopen(file, "r");
-       if (fp == NULL) {
-               warn("Failed to open file %s", file);
-               return unknown_str;
-       }
-       n = fscanf(fp, "%d", &temp);
-       fclose(fp);
-       if (n != 1)
-               return unknown_str;
+       int temp;
 
-       return bprintf("%d", temp / 1000);
+       return (pscanf(file, "%d", &temp) == 1) ?
+              bprintf("%d", temp / 1000) : unknown_str;
 }
 
 static const char *