MEMCACHED_DECREMENT(3)

💅 memcached_decrement — Incrementing and Decrementing Values 💅

okay bestie, welcome to memcached_decrement(3), brought to you by libmemcached-awesome. sit down, grab a boba, and let's talk about making numbers go up and also making them go down. it's giving very much "counter go brrr." 🎀

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✨ SYNOPSIS ✨

#include <libmemcached/memcached.h>

Compile and link with -lmemcached.

memcached_return_t memcached_increment(memcached_st *ptr, const char
*key, size_t key_length, uint32_t offset, uint64_t *value)

memcached_return_t memcached_decrement(memcached_st *ptr, const char
*key, size_t key_length, uint32_t offset, uint64_t *value)

memcached_return_t memcached_increment_with_initial(memcached_st *ptr,
const char *key, size_t key_length, uint64_t offset, uint64_t initial,
time_t expiration, uint64_t *value)

memcached_return_t memcached_decrement_with_initial(memcached_st *ptr,
const char *key, size_t key_length, uint64_t offset, uint64_t initial,
time_t expiration, uint64_t *value)

memcached_return_t memcached_increment_by_key(memcached_st *ptr, const
char *group_key, size_t group_key_length, const char *key, size_t
key_length, uint32_t offset, uint64_t *value)

memcached_return_t memcached_decrement_by_key(memcached_st *ptr, const
char *group_key, size_t group_key_length, const char *key, size_t
key_length, uint32_t offset, uint64_t *value)

memcached_return_t memcached_increment_with_initial_by_key(memcached_st
*ptr, const char *group_key, size_t group_key_length, const char *key,
size_t key_length, uint64_t offset, uint64_t initial, time_t expiration,
uint64_t *value)

memcached_return_t memcached_decrement_with_initial_by_key(memcached_st
*ptr, const char *group_key, size_t group_key_length, const char *key,
size_t key_length, uint64_t offset, uint64_t initial, time_t expiration,
uint64_t *value)

🌸 Parameters 🌸

• ptr — pointer to an initialized memcached_st struct. yes you have to actually initialize it first, no shortcuts babes 🙈
• group_key — key namespace 🫶
• group_key_length — length of the key namespace without any terminating zero. count it exactly, bestie, the zero is NOT invited to the party 💅
• key — the key 🔑
• key_length — length of the key without any terminating zero. same rule, the \0 stays home 🏠
• offset — offset to increment/decrement 📈📉
• initial — initial value if key does not exist and expiration is not MEMCACHED_EXPIRATION_NOT_ADD
• expiration — expiration as a unix timestamp or as relative expiration time in seconds ⏰
• value — the resulting value after initialization/increment/decrement ✨

🦋 Returns 🦋

memcached_return_t indicating success.

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👑 DESCRIPTION 👑

memcached(1) servers have the ability to increment and decrement keys. and like… heads up bestie: overflow and underflow are not detected 😭 the server is just not doing a vibe check on your math. this gives you the ability to use memcached to generate shared sequences of values. iconic behaviour honestly.

memcached_increment() takes a key and key_length and increments the value by the offset passed to it. the value is then returned via the uint32_t value pointer you pass to it. so it's giving ✨ bidirectional communication ✨.

memcached_decrement() takes a key and key_length and decrements the value by the offset passed to it. the value is then returned via the uint32_t value pointer you pass to it. the way that number just goes down?? obsessed.

memcached_increment_with_initial() takes a key and key_length and increments the value by the offset passed to it. and here's the plot twist 🌈 — if the object specified by key does not exist, one of two things may happen:

• if the expiration value is MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. like, it's over. no key, no add, no nada 💀
• for all other expiration values, the operation will succeed by seeding the value for that key with a initial value to expire with the provided expiration time.

the flags will be set to zero. the value is then returned via the uint32_t value pointer you pass to it. 🫶

memcached_increment_with_initial is only available when using the binary protocol. no binary protocol, no initial-value magic, periodt. 🎀

memcached_decrement_with_initial() takes a key and key_length and decrements the value by the offset passed to it. same plot twist energy: if the object specified by key does not exist, one of two things may happen —

• if the expiration value is MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. respectfully, it's not happening 💅
• for all other expiration values, the operation will succeed by seeding the value for that key with a initial value to expire with the provided expiration time.

the flags will be set to zero. the value is then returned via the uint32_t value pointer you pass to it. 😌

memcached_decrement_with_initial() is also only available when using the binary protocol. same rule, same drama. 🔥

memcached_increment_by_key(), memcached_decrement_by_key(), memcached_increment_with_initial_by_key(), and memcached_decrement_with_initial_by_key() are the master key equivalents of the above. basically the main character versions with group_key and group_key_length added to the cast 👑✨

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🌈 RETURN VALUE 🌈

A value of type memcached_return_t is returned. on success that value will be MEMCACHED_SUCCESS. use memcached_strerror() to translate this value to a printable string. so if something looks weird, that's your translator bestie 🫶

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🎀 SEE ALSO 🎀

memcached(1) libmemcached(3) memcached_strerror(3)

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and that's the whole page, bestie!! this was libmemcached-awesome, version 1.1, dated Jul 24, 2025 💖 slay responsibly, and remember: the counter only goes up if you tell it to. periodt. 🦋✨