我有一个PHP脚本，它可以触发机器上其他进程(Chromium实例(的启动。我想知道我是否能以某种方式获得当前系统上可用的内存量，这样我就知道我可以在不达到内存限制的情况下安全地启动另一个进程(例如，这可能会导致运行Redis实例的额外问题(。
我必须直接通过exec()进行某种系统调用吗？
您可以读取/proc/meminfo
下的示例
MemTotal: 4025840 kB
MemFree: 1189212 kB
MemAvailable: 1984948 kB
Buffers: 105404 kB
Cached: 883880 kB
SwapCached: 22012 kB
Active: 652224 kB
Inactive: 2055408 kB
Active(anon): 23560 kB
Inactive(anon): 1714568 kB
Active(file): 628664 kB
Inactive(file): 340840 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 2097148 kB
SwapFree: 1881452 kB
Dirty: 16 kB
Writeback: 0 kB
AnonPages: 1691600 kB
Mapped: 125292 kB
Shmem: 19780 kB
KReclaimable: 62736 kB
Slab: 88052 kB
SReclaimable: 62736 kB
SUnreclaim: 25316 kB
KernelStack: 2912 kB
PageTables: 11144 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 4110068 kB
Committed_AS: 2819784 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 15344 kB
VmallocChunk: 0 kB
Percpu: 1472 kB
HardwareCorrupted: 0 kB
AnonHugePages: 1536000 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
FileHugePages: 0 kB
FilePmdMapped: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 0 kB
DirectMap4k: 112492 kB
DirectMap2M: 4081664 kB
DirectMap1G: 2097152 kB
编辑：这里有一些关于如何获得值的示例代码，取自这里的
// mem usage
$get_meminfo = file('/proc/meminfo');
$meminfo_total = filter_var($get_meminfo[0], FILTER_SANITIZE_NUMBER_INT);
$meminfo_cached = filter_var($get_meminfo[2], FILTER_SANITIZE_NUMBER_INT);
$meminfo_free = filter_var($get_meminfo[1], FILTER_SANITIZE_NUMBER_INT);
if ($meminfo_total >= 10485760) {
$mem_total = round(($meminfo_total / 1048576), 2);
$mem_cached = round(($meminfo_cached / 1048576), 2);
$mem_free = round((($meminfo_free + $meminfo_cached) / 1048576), 2);
$mem_multiple = 'GB';
} else {
$mem_total = round(($meminfo_total / 1024), 2);
$mem_cached = round(($meminfo_cached / 1024), 2);
$mem_free = round((($meminfo_free + $meminfo_cached) / 1024), 2);
$mem_multiple = 'MB';
}
$mem = array(
'total' => $mem_total,
'cached' => $mem_cached,
'free' => $mem_free
);