Char array to hex string C

Question

I searched char  to hex string before but implementation I found adds some non-existent garbage at the end of hex string  I receive packets from socket  and I need to convert them to hex strings for log  null-terminated buffer   Can somebody advise me a good implementation for C     Thanks

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Supposing data is a char   Working example using std  hex   for int i 0  i lt data length    i      std  cout  lt  lt  std  hex  lt  lt   int data i     Or if you want to keep it all in a string   std  stringstream ss  for int i 0  i lt data length    i      ss  lt  lt  std  hex  lt  lt   int data i   std  string mystr   ss str

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Here is something   char const hex chars 16       0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F      for  int i   data  i  lt  data length    i         char const byte   data i        string    hex chars    byte  amp  0xF0    gt  gt  4        string    hex chars    byte  amp  0x0F    gt  gt  0

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Using boost    include  lt boost algorithm hex hpp gt   std  string s  tralalalala    std  string result  boost  algorithm  hex s begin    s end    std  back inserter result

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The simplest   int main         const char  str    hello       for  const char  p   str   p    p                printf   02x    p             printf   n        return 0

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You can try this code for converting bytes from packet to a null-terminated string and store to  string  variable for processing   const int buffer size   2048     variable for storing buffer as printable HEX string char data buffer size 2      receive message from socket int ret   recvfrom sock  buffer  sizeofbuffer  0  reinterpret cast lt SOCKADDR   gt   amp from    amp size      bytes converting cycle for  int i 0 j 0  i lt ret  i   j  2        char res 2        itoa  buffer i   amp  0xFF   res  16           if  res 1     0                data j    0x30  data j 1    res 0            else               data j    res 0   data j   1    res 1                  Null-Terminating the string with converted buffer data  ret   2     0    When we send message with hex bytes 0x01020E0F  variable  data  had char array with string  01020e0f

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You could use std  hex  Eg   std  cout  lt  lt  std  hex  lt  lt  packet

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Code snippet above provides incorrect byte order in string  so I fixed it a bit   char const hex 16       0    1    2    3    4    5    6    7    8    9    A      B   C   D   E   F     std  string byte 2 str char  bytes  int size      std  string str    for  int i   0  i  lt  size    i        const char ch   bytes i       str append  amp hex  ch   amp  0xF0   gt  gt  4   1       str append  amp hex ch  amp  0xF   1         return str

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I ve found good example here Display-char-as-Hexadecimal-String-in-C       std  vector lt char gt  randomBytes n     file read  amp randomBytes 0   n         Displaying bytes  method 1      --------------------------   for  auto amp  el   randomBytes      std  cout  lt  lt  std  setfill  0    lt  lt  std  setw 2   lt  lt  std  hex  lt  lt   0xff  amp   unsigned int el     std  cout  lt  lt    n         Displaying bytes  method 2      --------------------------   for  auto amp  el   randomBytes      printf   02hhx   el     std  cout  lt  lt    n     return 0       Method 1 as shown above is probably the more C   way       Cast to an unsigned int   Use std  hex to represent the value as hexadecimal digits   Use std  setw and std  setfill from  lt iomanip gt  to format   Note that you need to mask the cast int against 0xff to display   the least significant byte     0xff  amp   unsigned int el        Otherwise  if the highest bit is set the cast will result in the three   most significant bytes being set to ff

[c++] Char array to hex string C++

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