renamed calculate to detect

src/modules/os.c

@@ -1,14 +1,111 @@
 #include "fastfetch.h"
 
+#include <pthread.h>
+
 #define FF_OS_MODULE_NAME "OS"
 #define FF_OS_NUM_FORMAT_ARGS 12
 
+const FFOSResult* ffDetectOS(FFinstance* instance)
+{
+    static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+    static FFOSResult result;
+    static bool init = false;
+    pthread_mutex_lock(&mutex);
+    if(init)
+    {
+        pthread_mutex_unlock(&mutex);
+        return &result;
+    }
+    init = true;
+
+    FILE* osRelease = fopen("/etc/os-release", "r");
+
+    if(osRelease == NULL)
+        osRelease = fopen("/usr/lib/os-release", "r");
+
+    ffStrbufInitA(&result.error, 64);
+    if(osRelease == NULL)
+    {
+        ffStrbufAppendS(&result.error, "couldn't read /etc/os-release nor /usr/lib/os-release");
+        return &result;
+    }
+
+    ffStrbufInitA(&result.systemName, 256);
+    ffStrbufInitA(&result.name, 256);
+    ffStrbufInitA(&result.prettyName, 256);
+    ffStrbufInitA(&result.id, 256);
+    ffStrbufInitA(&result.idLike, 256);
+    ffStrbufInitA(&result.variant, 256);
+    ffStrbufInitA(&result.variantID, 256);
+    ffStrbufInitA(&result.version, 256);
+    ffStrbufInitA(&result.versionID, 256);
+    ffStrbufInitA(&result.codename, 256);
+    ffStrbufInitA(&result.buildID, 256);
+    ffStrbufInitA(&result.architecture, 256);
+    ffStrbufInitA(&result.error, 256);
+
+    ffStrbufSetS(&result.systemName, instance->state.utsname.sysname);
+    ffStrbufSetS(&result.architecture, instance->state.utsname.machine);
+
+    char* line = NULL;
+    size_t len = 0;
+
+    // Documentation of the fields:
+    // https://www.freedesktop.org/software/systemd/man/os-release.html
+    while (getline(&line, &len, osRelease) != -1)
+    {
+        sscanf(line, "NAME=%[^\n]", result.name.chars);
+        sscanf(line, "NAME=\"%[^\"]+", result.name.chars);
+        sscanf(line, "PRETTY_NAME=%[^\n]", result.prettyName.chars);
+        sscanf(line, "PRETTY_NAME=\"%[^\"]+", result.prettyName.chars);
+        sscanf(line, "ID=%[^\n]", result.id.chars);
+        sscanf(line, "ID=\"%[^\"]+", result.id.chars);
+        sscanf(line, "ID_LIKE=%[^\n]", result.idLike.chars);
+        sscanf(line, "ID_LIKE=\"%[^\"]+", result.idLike.chars);
+        sscanf(line, "VARIANT=%[^\n]", result.variant.chars);
+        sscanf(line, "VARIANT=\"%[^\"]+", result.variant.chars);
+        sscanf(line, "VARIANT_ID=%[^\n]", result.variantID.chars);
+        sscanf(line, "VARIANT_ID=\"%[^\"]+", result.variantID.chars);
+        sscanf(line, "VERSION=%[^\n]", result.version.chars);
+        sscanf(line, "VERSION=\"%[^\"]+", result.version.chars);
+        sscanf(line, "VERSION_ID=%[^\n]", result.versionID.chars);
+        sscanf(line, "VERSION_ID=\"%[^\"]+", result.versionID.chars);
+        sscanf(line, "VERSION_CODENAME=%[^\n]", result.codename.chars);
+        sscanf(line, "VERSION_CODENAME=\"%[^\"]+", result.codename.chars);
+        sscanf(line, "BUILD_ID=%[^\n]", result.buildID.chars);
+        sscanf(line, "BUILD_ID=\"%[^\"]+", result.buildID.chars);
+    }
+
+    ffStrbufRecalculateLength(&result.systemName);
+    ffStrbufRecalculateLength(&result.name);
+    ffStrbufRecalculateLength(&result.prettyName);
+    ffStrbufRecalculateLength(&result.id);
+    ffStrbufRecalculateLength(&result.idLike);
+    ffStrbufRecalculateLength(&result.variant);
+    ffStrbufRecalculateLength(&result.variantID);
+    ffStrbufRecalculateLength(&result.version);
+    ffStrbufRecalculateLength(&result.versionID);
+    ffStrbufRecalculateLength(&result.codename);
+    ffStrbufRecalculateLength(&result.buildID);
+    ffStrbufRecalculateLength(&result.architecture);
+    ffStrbufRecalculateLength(&result.error);
+
+    if(line != NULL)
+        free(line);
+
+    fclose(osRelease);
+
+    pthread_mutex_unlock(&mutex);
+
+    return &result;
+}
+
 void ffPrintOS(FFinstance* instance)
 {
     if(ffPrintFromCache(instance, FF_OS_MODULE_NAME, &instance->config.osKey, &instance->config.osFormat, FF_OS_NUM_FORMAT_ARGS))
         return;
 
-    const FFOSResult* result = ffCalculateOS(instance);
+    const FFOSResult* result = ffDetectOS(instance);
 
     if(result->error.length > 0)
     {