1MEMCACHED_APPEND(3)              libmemcached              MEMCACHED_APPEND(3)
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NAME

6       memcached_append - Appending to or Prepending to data on the server
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8       Appending or Prepending to data on the server
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SYNOPSIS

11       #include <libmemcached/memcached.h>
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13       memcached_return_t      memcached_prepend(memcached_st *ptr,      const
14       char *key, size_t key_length, const  char *value,  size_t value_length,
15       time_t expiration, uint32_t flags)
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17       memcached_return_t memcached_append(memcached_st *ptr, const char *key,
18       size_t key_length, const char *value, size_t value_length, time_t expi‐
19       ration, uint32_t flags)
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21       memcached_return_t   memcached_prepend_by_key(memcached_st *ptr,  const
22       char *group_key,     size_t group_key_length,     const      char *key,
23       size_t key_length, const char *value, size_t value_length, time_t expi‐
24       ration, uint32_t flags)
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26       memcached_return_t   memcached_append_by_key(memcached_st *ptr,   const
27       char *group_key,      size_t group_key_length,     const     char *key,
28       size_t key_length, const char *value, size_t value_length, time_t expi‐
29       ration, uint32_t flags)
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31       Compile and link with -lmemcached
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DESCRIPTION

34       memcached_prepend() and memcached_append are used to modify information
35       on a server. All methods take a  key,  and  its  length  to  store  the
36       object.  Keys are currently limited to 250 characters when using either
37       a version of memcached which is 1.4 or below, or when  using  the  text
38       protocol. You must supply both a value and a length. Optionally you may
39       test an expiration time for the object and a 16 byte value (it is meant
40       to be used as a bitmap). "flags" is a 4byte space that is stored along‐
41       side of the main value. Many sub libraries make use of this  field,  so
42       in most cases users should avoid making use of it.
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44       memcached_prepend()  places  a segment of data before the last piece of
45       data stored. Currently expiration and key are not used in the server.
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47       memcached_append() places a segment of data at  the  end  of  the  last
48       piece  of data stored. Currently expiration and key are not used in the
49       server.
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51       memcached_prepend_by_key() and memcached_append_by_key()  methods  both
52       behave  in  a  similar method as the non key methods. The difference is
53       that they use their group_key parameter to map  objects  to  particular
54       servers.
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56       If  you  are looking for performance, memcached_set() with non-blocking
57       IO is the fastest way to store data on the server.
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59       All of the  above  functions  are  testsed  with  the  MEMCACHED_BEHAV‐
60       IOR_USE_UDP behavior enabled. However, when using these operations with
61       this behavior on, there are limits to the size  of  the  payload  being
62       sent  to the server.  The reason for these limits is that the Memcached
63       Server does not allow multi-datagram requests and  the  current  server
64       implementation  sets  a  datagram  size  to 1400 bytes. Due to protocol
65       overhead, the actual limit of the user supplied data is less than  1400
66       bytes  and  depends  on  the  protocol in use as, well as the operation
67       being executed. When running with the binary protocol, MEMCACHED_BEHAV‐
68       IOR_BINARY_PROTOCOL,  the  size of the key,value, flags and expiry com‐
69       bined may not exceed 1368 bytes. When running with the ASCII  protocol,
70       the  exact  limit  fluctuates depending on which function is being exe‐
71       cuted and whether the function is a cas operation or not.  For  non-cas
72       ASCII  set operations, there are at least 1335 bytes available to split
73       among the key, key_prefix, and value; for cas  ASCII  operations  there
74       are  at  least  1318 bytes available to split among the key, key_prefix
75       and value. If the  total  size  of  the  command,  including  overhead,
76       exceeds 1400 bytes, a MEMCACHED_WRITE_FAILURE will be returned.
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RETURN

79       All  methods return a value of type memcached_return_t.  On success the
80       value will be MEMCACHED_SUCCESS.  Use memcached_strerror() to translate
81       this value to a printable string.
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HOME

84       To find out more information please check: http://libmemcached.org/
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SEE ALSO

87       memcached(1) libmemached(3) memcached_strerror(3) memcached_set(3) mem‐
88       cached_add(3) memcached_cas(3) memcached_replace(3)
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AUTHOR

91       Brian Aker
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94       2011-2013, Brian Aker DataDifferential, http://datadifferential.com/
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991.0.16                         January 31, 2013            MEMCACHED_APPEND(3)
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