It is "pseudo-shell" that will only execute provided -c command. Might be helpful for sshd users configured with "ForcedCommand" and "ChrootDirectory". (example with further references: https://goo.gl/TjhrWd ). License: This is trivial code snippet directly based on documentation and C specification, please consider it public domain.

only_exec_command.c

#include <unistd.h>
// compile with: gcc only_exec_command.c -static -o only_exec_command
// It is "pseudo-shell" that will only execute provided -c command.
// Usage : ./only_exec_command -c /bin/echo This is test

// Please note that this is far from perfect. It should actually parse and split string
// provided in argv[2], like shlex.Split in python. However, it's enought for my application
// of running one binary specified in ForceCommand sshd_config option.

int main(int argc, char **argv){
        if (argc<3) return -1;
        if (argv[1][0] != '-' || argv[1][1] != 'c' || argv[1][2] != '\0')
                return -1;
        execv(argv[2], &(argv[2]));
        return 0;
}