我有这段代码可以通过@srcset属性列出图像的大小：
cat <<EOF | xidel -s - -e 'extract(//@srcset,"(\d+w)",1,"*")'
<img ... srcset="https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-696x457.jpg 696w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-220x144.jpg 220w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-300x197.jpg 300w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-768x504.jpg 768w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-475x312.jpg 475w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w,
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-741x486.jpg 741w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-640x420.jpg 640w" />
EOF
696w
220w
300w
768w
475w
800w
741w
640w
如何使用Xidel获得最佳分辨率？在这种情况下，仅800w？
最大大小可以在开头，结尾或中间（随机顺序）。
Xidel预期输出：
cat <<EOF | xidel -s - -e '?'
<img ... srcset="https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-696x457.jpg 696w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-220x144.jpg 220w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-300x197.jpg 300w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-768x504.jpg 768w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-475x312.jpg 475w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w,
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-741x486.jpg 741w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-640x420.jpg 640w" />
EOF
800w
或输出完整的URL：
cat <<EOF | xidel -s - -e '?'
<img ... srcset="https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-696x457.jpg 696w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-220x144.jpg 220w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-300x197.jpg 300w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-768x504.jpg 768w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-475x312.jpg 475w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w,
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-741x486.jpg 741w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-640x420.jpg 640w" />
EOF
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg
答案 0 :(得分：0)
要提取最大宽度，只需在其周围放置max()：-e 'max(extract(//@srcset,"(\d+w)",1,"*"))'。
要提取最大宽度的网址，您首先必须拆分每个网址：
$ cat <<EOF | xidel -s - -e 'tokenize(//@srcset,", ")'
<img srcset="https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-696x457.jpg 696w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-220x144.jpg 220w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-300x197.jpg 300w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-768x504.jpg 768w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-475x312.jpg 475w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-741x486.jpg 741w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-640x420.jpg 640w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w" />
EOF
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-696x457.jpg 696w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-220x144.jpg 220w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-300x197.jpg 300w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-768x504.jpg 768w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-475x312.jpg 475w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-741x486.jpg 741w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-640x420.jpg 640w
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w
然后，令我惊讶的是，您可以再次将max()包裹起来：
$ cat <<EOF | xidel -s - -e 'max(tokenize(//@srcset,", "))'
<img srcset="https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-696x457.jpg 696w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-220x144.jpg 220w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-300x197.jpg 300w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-768x504.jpg 768w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-475x312.jpg 475w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-741x486.jpg 741w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu-640x420.jpg 640w, https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w" />
EOF
https://www.jewishpress.com/wp-content/uploads/Billionaire-Arnon-Milchan-and-PM-Benjamin-Netanyahu.jpg 800w
仅返回网址，您可以执行以下操作：-e 'substring-before(max(tokenize(//@srcset,", "))," ")'。