bits | A java library for handling bit level data | Serialization library

All basic integer types in Java are signed. To be exact, byte, short, int and long are signed big endian two complement integers. That means that they run from - 2^n-1 to 2^n-1 - 1 where n is the number of bits - 8 for a byte (Byte.SIZE in Java), and therefore the range is from -128 to 127.

The number you are using is always an integer; number literals always are. However, the integer is actually the value 0x000000FF in hexadecimals. That cannot be stored as it is higher than 127. You can however do an explicit conversion; your value does consist of 8 bits after all.

Here I'm wondering about the line [in s_client]
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384

You're apparently using OpenSSL 1.0.2, where that's a basically useless relic. Back in the days when OpenSSL supported SSLv2 (mostly until 2010, although almost no one used it much after 2000), the ciphersuite values used for SSLv3 and up (including all TLS, but before 2014 OpenSSL didn't implement higher than TLS1.0) were structured differently than those used for SSLv2, so it was important to qualify the ciphersuite by the 'universe' it existed in. It has almost nothing to do with the protocol version actually used, which appears later in the session-param decode:

here shows a possible error:

3221225620 (0xC0000094): Zero Division Error

means that a divisor in your code could sometime be zero.

as for your code(line 20: d = d % n;), when your n is 0, the output will show return value 3221225620

so please check your data in "input.txt"

The code just needs to declare buf[11] so there's room to append the CRC, then append the CRC. Some other were changes made to work with Visual Studio (the indented blocks used for local variables). The CRC calculation could be simplified.

You have a few issues in your code, the ones I can spot right away are:

if(str[0]='\0') - this is an assignment, not a comparison. Your entire string will be replaced with \0-characters - no characters will be skipped because this:

if(str[0]!='x'||str[0]!='X') is always true. Ask yourself if x is different from x (false) OR X (true). False or true = true.

The check should be implemented something like (str[0] != 'x' && str[0] != 'X').

Edit: One more issue.

The overall logic will not work (-ish). The part where you run through the string and compress it is correct enough. But you try to run to the end and then print the string, however at that point you are only holding the end of the string (the null termination), so no matter what else you have done you will only print that (aka. print nothing).

Instead, once you are done compressing the xs out of the string, you need to return to the beginning of the string and then print that. The easy way is to print in main, or you can split your function into an outer+inner function like:

A few bits of documentation to start:

From man 3 system's caveats section:

Do not use system() from a privileged program (a set-user-ID or set-group-ID program, or a program with capabilities) because strange values for some environment variables might be used to subvert system integrity. For example, PATH could be manipulated so that an arbitrary program is executed with privilege. Use the exec(3) family of functions instead, but not execlp(3) or execvp(3) (which also use the PATH environment variable to search for an executable).

system() will not, in fact, work properly from programs with set-user-ID or set-group-ID privileges on systems on which /bin/sh is bash version 2: as a security measure, bash 2 drops privileges on startup. Debian uses a different shell, dash(1), which does not do this when invoked as sh.)

And from the bash manual's description of the -p command line argument (Emphasis added):

Turn on privileged mode. In this mode, the $BASH_ENV and $ENV files are not processed, shell functions are not inherited from the environment, and the SHELLOPTS, BASHOPTS, CDPATH and GLOBIGNORE variables, if they appear in the environment, are ignored. If the shell is started with the effective user (group) id not equal to the real user (group) id, and the -p option is not supplied, these actions are taken and the effective user id is set to the real user id. If the -p option is supplied at startup, the effective user id is not reset. Turning this option off causes the effective user and group ids to be set to the real user and group ids.

So even if your /bin/sh doesn't drop privileges when run, bash will when it's run in turn without explicitly telling it not to.

So one option is to scrap using system(), and do a lower-level fork()/exec() of bash -p your-script-name.

Some other approaches to allowing scripts to run at elevated privileges are mentioned in Allow suid on shell scripts. In particular the answer using setuid() to change the real UID looks like it's worth investigating.

Or configure sudo to not require a password for a particular script for a given user.

Also see Why should I not #include ?

You missed to set the alignment. By default OpenGL assumes that the start of each row of the raster is aligned to 4 bytes. This is because the GL_UNPACK_ALIGNMENT parameter by default is 4. Each row in the raster has 5 bytes (40 / 8 = 5). Therefore you need to change the alignment to 1:

You're looking at random numbers uniformly distributed between 0 and 18,446,744,073,709,551,615 (UINT64_MAX). All numbers between 10,000,000,000,000,000,000 and 18,446,744,073,709,551,615 start with a 1, so the skewed distribution is to be expected.

1. Your universal reference resolves to int for g(2) and int& for g(i)
2. You can't have a std::vector of a reference type (see this explanation).