C language access to Redis using Hiredis

Hiredisis a simple C client library of the Redis database. It is minimalist because it only adds minimal support for the Protocol, but at the same time it uses a high-level printf-like API, so it is very easy to use for C programming users accustomed to printf style, and the API does not explicitly bind each Redis command.

Github:https://github.com/redis/hiredis

Installing Hiredis

Compile and install:

gitcdmakemake install

The following is make install the output:

mkdir -p /usr/local/include/hiredis /usr/local/include/hiredis/adapters /usr/local/libcp -pPR hiredis.h async.h read.h sds.h /usr/local/include/hirediscp -pPR adapters/*.h /usr/local/include/hiredis/adapterscp -pPR libhiredis.so /usr/local/lib/libhiredis.so.0.13cd /usr/local/lib && ln -sf libhiredis.so.0.13 libhiredis.socp -pPR libhiredis.a /usr/local/libmkdir -p /usr/local/lib/pkgconfigcp -pPR hiredis.pc /usr/local/lib/pkgconfig

Copy the dynamic link library to Lib:

cp

If the 32 system only needs to run:

cp libhiredis.so /usr/lib

You also need to update the dynamic-link library cache:

/sbin/ldconfig

ldconfigThe purpose of the command is to search for a shareable dynamic-link library (in the form of a format) in the default search directory and in the /lib /usr/lib directories listed in the dynamic library configuration file, and to /etc/ld.so.conf create the lib*.so* ld.so connection and cache files required for the dynamic loader (). The cache file defaults to /etc/ld.so.cache , this file holds the ordered list of dynamic link library names, in order to let the dynamic link library for the system to share, need to run the dynamic Link Library Management command ldconfig , this execution program is stored in the/sbin directory.

ldconfigTypically runs at system startup, and when a user installs a new dynamic-link library, it is necessary to run the command manually.

Client code

TEST.c

#include <stdio.h>  #include   int main()  {      redisContext* conn = redisConnect("127.0.0.1"6379);      if(conn->err)   printf("connection error:%s\n", conn->errstr);        "set foo 1234");      freeReplyObject(reply);        "get foo");        printf("%s\n", reply->str);      freeReplyObject(reply);        redisFree(conn);        return0;  }

And then:

gcc test.c -o test -lhiredis

Compiling is sure to use the -l connect dynamic library.

-lstackTells the compiler to link the lhiredis library.

Run:

$ ./test1234

Function prototype Redisconnect

redisContext *redisConnect(constcharint port)

Note: This function is used to connect the Redis database with the IP address and port of the database, and the general Redis database has a port of 6379.

The function returns a struct body redisContext .

Rediscommand

voidconstchar *format, ...);

Description: The function executes commands, just like SQL statements in SQL database, only executes the redis operation commands in the database, the first parameter is returned when the database is connected redisContext , and the remaining arguments are variables, as in the case of C standard function printf functions.

The return value for the void* general cast becomes redisReply the type for further processing.

Freereplyobject

void freeReplyObject(void *reply);

Description: Releases the redisCommand occupied memory returned after execution redisReply .

Redisfree

void redisFree(redisContext *c);

Description: Releases the redisConnect() resulting connection.

Reference

1. Redis: Installation, configuration, operation and simple code example (C-language client)-CSDN Blog
8724907
2. C-language access to Redis (Hiredis)-CSDN Blog
38015765
3. Error while loading shared libraries problem Resolution-CSDN Blog
50971142
4, ldconfig command _linux ldconfig command usage Detailed: Dynamic link Library Management command
Http://man.linuxde.net/ldconfig?mstqrk=qdwrv1

C language access to Redis using Hiredis