fastfetch/src/detection/cpuusage/cpuusage_linux.c

#include "fastfetch.h"
#include "detection/cpuusage/cpuusage.h"
#include "common/debug.h"
#include "common/io.h"

#include <stdio.h>
#include <inttypes.h>

const char* ffGetCpuUsageInfo(FFlist* cpuTimes) {
    char buf[PROC_FILE_BUFFSIZ];
    ssize_t nRead = ffReadFileData("/proc/stat", ARRAY_SIZE(buf) - 1, buf);
    if (nRead < 0) {
        FF_DEBUG("Reading \"/proc/stat\" failed: %s", strerror(errno));
#ifdef __ANDROID__
        return "Accessing \"/proc/stat\" is restricted on Android O+";
#else
        return "ffReadFileData(\"/proc/stat\", ARRAY_SIZE(buf) - 1, buf) failed";
#endif
    }
    buf[nRead] = '\0';

    // Skip first line
    char* start = nullptr;
    if ((start = strchr(buf, '\n')) == nullptr) {
        FF_DEBUG("skip first line failed");
        return "skip first line failed";
    }
    ++start;

    uint64_t user = 0, nice = 0, system = 0, idle = 0, iowait = 0, irq = 0, softirq = 0;
    char* token = nullptr;
    while ((token = strchr(start, '\n'))) {
        if (sscanf(start, "cpu%*d%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%*[^\n]\n", &user, &nice, &system, &idle, &iowait, &irq, &softirq) == 7) {
            uint64_t inUse = user + nice + system + irq + softirq;
            uint64_t total = inUse + idle + iowait;

            FFCpuUsageInfo* info = FF_LIST_ADD(FFCpuUsageInfo, *cpuTimes);
            *info = (FFCpuUsageInfo) {
                .inUseAll = inUse,
                .totalAll = total,
            };
        } else {
            break;
        }
        start = token + 1;
    }

    return nullptr;
}