如何結合popen和file_get_contents從命令輸出中讀取數據？

在PHP中處理外部命令並讀取其輸出通常有多種方式，例如使用exec 、 shell_exec 、 popen等函數。其中， popen提供了一種面向流的方式來讀取命令行工具的輸出，這種方式在處理持續輸出或需要分段讀取的場景下尤其實用。

此外， file_get_contents通常用於讀取文件或URL內容，但你可能不知道，它同樣可以用來讀取通過popen創建的流。本文將介紹如何結合這兩個函數，從命令的輸出中高效讀取數據。

一、popen 簡介

popen的函數原型如下：

 resource popen(string $command, string $mode)

它用於執行一個命令，並打開一個可以讀取或寫入的文件指針。 $mode可以是'r' （讀取）或'w' （寫入），不過我們這里關注的是讀取模式。

二、file_get_contents 讀取流

通常我們使用file_get_contents來讀取靜態文件或者像http://m66.net/data.json這樣的遠程資源。但由於file_get_contents支持讀取任何流資源，它也可以用於讀取通過popen打開的命令輸出。

三、示例：讀取ls命令輸出

下面是一個實際示例，我們將執行ls命令，並讀取其輸出內容：

<div class="contain-inline-size rounded-2xl border-[0.5px] border-token-border-medium relative bg-token-sidebar-surface-primary"><div class="flex items-center text-token-text-secondary px-4 py-2 text-xs font-sans justify-between h-9 bg-token-sidebar-surface-primary dark:bg-token-main-surface-secondary select-none rounded-t-2xl"> php </div><div class="sticky top-9"><div class="absolute end-0 bottom-0 flex h-9 items-center pe-2"><div class="bg-token-sidebar-surface-primary text-token-text-secondary dark:bg-token-main-surface-secondary flex items-center gap-4 rounded-sm px-2 font-sans text-xs"><button class="flex gap-1 items-center select-none py-1" aria-label="複製"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="icon-xs"><path d="M12.668 10.667C12.668 9.95614 12.668 9.46258 12.6367 9.0791C12.6137 8.79732 12.5758 8.60761 12.5244 8.46387L12.4688 8.33399C12.3148 8.03193 12.0803 7.77885 11.793 7.60254L11.666 7.53125C11.508 7.45087 11.2963 7.39395 10.9209 7.36328C10.5374 7.33197 10.0439 7.33203 9.33301 7.33203H6.5C5.78896 7.33203 5.29563 7.33195 4.91211 7.36328C4.63016 7.38632 4.44065 7.42413 4.29688 7.47559L4.16699 7.53125C3.86488 7.68518 3.61186 7.9196 3.43555 8.20703L3.36524 8.33399C3.28478 8.49198 3.22795 8.70352 3.19727 9.0791C3.16595 9.46259 3.16504 9.95611 3.16504 10.667V13.5C3.16504 14.211 3.16593 14.7044 3.19727 15.0879C3.22797 15.4636 3.28473 15.675 3.36524 15.833L3.43555 15.959C3.61186 16.2466 3.86474 16.4807 4.16699 16.6348L4.29688 16.6914C4.44063 16.7428 4.63025 16.7797 4.91211 16.8027C5.29563 16.8341 5.78896 16.835 6.5 16.835H9.33301C10.0439 16.835 10.5374 16.8341 10.9209 16.8027C11.2965 16.772 11.508 16.7152 11.666 16.6348L11.793 16.5645C12.0804 16.3881 12.3148 16.1351 12.4688 15.833L12.5244 15.7031C12.5759 15.5594 12.6137 15.3698 12.6367 15.0879C12.6681 14.7044 12.668 14.211 12.668 13.5V10.667ZM13.998 12.665C14.4528 12.6634 14.8011 12.6602 15.0879 12.6367C15.4635 12.606 15.675 12.5492 15.833 12.4688L15.959 12.3975C16.2466 12.2211 16.4808 11.9682 16.6348 11.666L16.6914 11.5361C16.7428 11.3924 16.7797 11.2026 16.8027 10.9209C16.8341 10.5374 16.835 10.0439 16.835 9.33301V6.5C16.835 5.78896 16.8341 5.29563 16.8027 4.91211C16.7797 4.63025 16.7428 4.44063 16.6914 4.29688L16.6348 4.16699C16.4807 3.86474 16.2466 3.61186 15.959 3.43555L15.833 3.36524C15.675 3.28473 15.4636 3.22797 15.0879 3.19727C14.7044 3.16593 14.211 3.16504 13.5 3.16504H10.667C9.9561 3.16504 9.46259 3.16595 9.0791 3.19727C8.79739 3.22028 8.6076 3.2572 8.46387 3.30859L8.33399 3.36524C8.03176 3.51923 7.77886 3.75343 7.60254 4.04102L7.53125 4.16699C7.4508 4.32498 7.39397 4.53655 7.36328 4.91211C7.33985 5.19893 7.33562 5.54719 7.33399 6.00195H9.33301C10.022 6.00195 10.5791 6.00131 11.0293 6.03809C11.4873 6.07551 11.8937 6.15471 12.2705 6.34668L12.4883 6.46875C12.984 6.7728 13.3878 7.20854 13.6533 7.72949L13.7197 7.87207C13.8642 8.20859 13.9292 8.56974 13.9619 8.9707C13.9987 9.42092 13.998 9.97799 13.998 10.667V12.665ZM18.165 9.33301C18.165 10.022 18.1657 10.5791 18.1289 11.0293C18.0961 11.4302 18.0311 11.7914 17.8867 12.1279L17.8203 12.2705C17.5549 12.7914 17.1509 13.2272 16.6553 13.5313L16.4365 13.6533C16.0599 13.8452 15.6541 13.9245 15.1963 13.9619C14.8593 13.9895 14.4624 13.9935 13.9951 13.9951C13.9935 14.4624 13.9895 14.8593 13.9619 15.1963C13.9292 15.597 13.864 15.9576 13.7197 16.2939L13.6533 16.4365C13.3878 16.9576 12.9841 17.3941 12.4883 17.6982L12.2705 17.8203C11.8937 18.0123 11.4873 18.0915 11.0293 18.1289C10.5791 18.1657 10.022 18.165 9.33301 18.165H6.5C5.81091 18.165 5.25395 18.1657 4.80371 18.1289C4.40306 18.0962 4.04235 18.031 3.70606 17.8867L3.56348 17.8203C3.04244 17.5548 2.60585 17.151 2.30176 16.6553L2.17969 16.4365C1.98788 16.0599 1.90851 15.6541 1.87109 15.1963C1.83431 14.746 1.83496 14.1891 1.83496 13.5V10.667C1.83496 9.978 1.83432 9.42091 1.87109 8.9707C1.90851 8.5127 1.98772 8.10625 2.17969 7.72949L2.30176 7.51172C2.60586 7.0159 3.04236 6.6122 3.56348 6.34668L3.70606 6.28027C4.04237 6.136 4.40303 6.07083 4.80371 6.03809C5.14051 6.01057 5.53708 6.00551 6.00391 6.00391C6.00551 5.53708 6.01057 5.14051 6.03809 4.80371C6.0755 4.34588 6.15483 3.94012 6.34668 3.56348L6.46875 3.34473C6.77282 2.84912 7.20856 2.44514 7.72949 2.17969L7.87207 2.11328C8.20855 1.96886 8.56979 1.90385 8.9707 1.87109C9.42091 1.83432 9.978 1.83496 10.667 1.83496H13.5C14.1891 1.83496 14.746 1.83431 15.1963 1.87109C15.6541 1.90851 16.0599 1.98788 16.4365 2.17969L16.6553 2.30176C17.151 2.60585 17.5548 3.04244 17.8203 3.56348L17.8867 3.70606C18.031 4.04235 18.0962 4.40306 18.1289 4.80371C18.1657 5.25395 18.165 5.81091 18.165 6.5V9.33301Z"></path></svg>複製<span class="" data-state="closed"><button class="flex items-center gap-1 py-1 select-none"></span> <svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="icon-xs"><path d="M12.0303 4.11328C13.4406 2.70317 15.7275 2.70305 17.1377 4.11328C18.5474 5.52355 18.5476 7.81057 17.1377 9.2207L10.8457 15.5117C10.522 15.8354 10.2868 16.0723 10.0547 16.2627L9.82031 16.4395C9.61539 16.5794 9.39783 16.7003 9.1709 16.7998L8.94141 16.8916C8.75976 16.9582 8.57206 17.0072 8.35547 17.0518L7.59082 17.1865L5.19727 17.5859C5.05455 17.6097 4.90286 17.6358 4.77441 17.6455C4.67576 17.653 4.54196 17.6555 4.39648 17.6201L4.24707 17.5703C4.02415 17.4746 3.84119 17.3068 3.72559 17.0957L3.67969 17.0029C3.59322 16.8013 3.59553 16.6073 3.60547 16.4756C3.61519 16.3473 3.6403 16.1963 3.66406 16.0537L4.06348 13.6602C4.1638 13.0582 4.22517 12.6732 4.3584 12.3096L4.45117 12.0791C4.55073 11.8521 4.67152 11.6346 4.81152 11.4297L4.9873 11.1953C5.17772 10.9632 5.4146 10.728 5.73828 10.4043L12.0303 4.11328ZM6.67871 11.3447C6.32926 11.6942 6.14542 11.8803 6.01953 12.0332L5.90918 12.1797C5.81574 12.3165 5.73539 12.4618 5.66895 12.6133L5.60742 12.7666C5.52668 12.9869 5.48332 13.229 5.375 13.8789L4.97656 16.2725L4.97559 16.2744H4.97852L7.37207 15.875L8.08887 15.749C8.25765 15.7147 8.37336 15.6839 8.4834 15.6436L8.63672 15.5811C8.78817 15.5146 8.93356 15.4342 9.07031 15.3408L9.2168 15.2305C9.36965 15.1046 9.55583 14.9207 9.90527 14.5713L14.8926 9.58301L11.666 6.35742L6.67871 11.3447ZM16.1963 5.05371C15.3054 4.16304 13.8616 4.16305 12.9707 5.05371L12.6074 5.41602L15.833 8.64258L16.1963 8.2793C17.0869 7.38845 17.0869 5.94456 16.1963 5.05371Z"></path><path d="M4.58301 1.7832C4.72589 1.7832 4.84877 1.88437 4.87695 2.02441C4.99384 2.60873 5.22432 3.11642 5.58398 3.50391C5.94115 3.88854 6.44253 4.172 7.13281 4.28711C7.27713 4.3114 7.38267 4.43665 7.38281 4.58301C7.38281 4.7295 7.27723 4.8546 7.13281 4.87891C6.44249 4.99401 5.94116 5.27746 5.58398 5.66211C5.26908 6.00126 5.05404 6.43267 4.92676 6.92676L4.87695 7.1416C4.84891 7.28183 4.72601 7.38281 4.58301 7.38281C4.44013 7.38267 4.31709 7.28173 4.28906 7.1416C4.17212 6.55728 3.94179 6.04956 3.58203 5.66211C3.22483 5.27757 2.72347 4.99395 2.0332 4.87891C1.88897 4.85446 1.7832 4.72938 1.7832 4.58301C1.78335 4.43673 1.88902 4.3115 2.0332 4.28711C2.72366 4.17203 3.22481 3.88861 3.58203 3.50391C3.94186 3.11638 4.17214 2.60888 4.28906 2.02441L4.30371 1.97363C4.34801 1.86052 4.45804 1.78333 4.58301 1.7832Z"></path></svg>編輯</div></div></div><div class="overflow-y-auto p-4" dir="ltr"><?php
$cmd = 'ls -la'; // 你可以替換成任何你想執行的命令
$handle = popen($cmd, 'r');

if (is_resource($handle)) {
    $output = stream_get_contents($handle);
    pclose($handle);
    echo "<pre>$output