"Interesting" System Calls In order to be able to properly understand the output of strace, lets first examine a list of interesting system calls that repeat often. For full details about a system call - refer to its manual page. open - opens a given file for reading or for writing. returns a file descriptor that may be used to access the file. close - close a previously opened file. read, write - read from/write to a given file descriptor. execve - load and execute a given binary file under the current process.