RPUSHX(3valkey)

📦
version 9.0.6 · 2 versions
, in fedora 44

💖 RPUSHX — the "only if you already exist" list push 💖

okay so bestie, welcome to rpushx(3valkey), straight out of the Valkey Command Manual ✨ this one's a little diva of a command: it appends one or more elements to a list, but only when the list is already there. no list, no push, no drama. 💅

✨ NAME ✨

rpushx — appends one or more elements to a list only when the list exists. like, it's giving "i'll show up but only if the party's already happening" 🎀

🌸 SYNOPSIS 🌸

RPUSHX key element [element...]

🦋 DESCRIPTION 🦋

So here's the tea 🍓 — RPUSHX inserts the values you give it at the tail of the list stored at key, but only if key already exists and holds a list. That's the whole vibe check.

And listen, this is the important part: in contrary to valkey-rpush(7) RPUSH, no operation will be performed when key does not yet exist. Not a "hmm maybe", not a "let me create one for you" — literally nothing happens. it's giving unbothered. 💀

💜 REPLY 💜

valkey-protocol(7) Integer reply: the length of the list after the push operation. so like, a number, bestie. the new count. 📏

⭐ COMPLEXITY ⭐

O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments. fast fast fast, no cap 🔥

👑 ACL CATEGORIES 👑

  • @fast
  • @list
  • @write

three little badges, iconic behavior ✨

🌈 HISTORY 🌈

  1. Available since: 2.2.0 — she's been around a minute 🕰️
  2. Changed in 4.0.0: Accepts multiple element arguments. glow-up era 🦋

🎀 EXAMPLES 🎀

watch her work:

127.0.0.1:6379> RPUSH mylist "Hello"
(integer) 1
127.0.0.1:6379> RPUSHX mylist "World"
(integer) 2
127.0.0.1:6379> RPUSHX myotherlist "World"
(integer) 0
127.0.0.1:6379> LRANGE mylist 0 -1
1) "Hello"
2) "World"
127.0.0.1:6379> LRANGE myotherlist 0 -1
(empty array)

see how mylist existed so RPUSHX was like "say less" and gave us 2, but myotherlist was not a thing so she returned 0 and that list stayed a whole empty array? 😭 that's the entire personality of this command right there. periodt.

🫶 SEE ALSO 🫶

the whole list-command friend group, iykyk 💜

lowkey reminder: if key doesn't exist, RPUSHX does absolutely nothing. don't come crying to me when your list is still missing. 🙈

okay that's the page bestie, go forth and push responsibly 💖 this was Valkey 9.0.0, dated 2025-10-21 — mwah, bye! 🧚✨

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