Your question isn't really that clear; you can create a new file when exiting any of the editor programs, by using I/O redirection, or the touch command.
cat file name
The 'touch' command creates a new empty file in Unix.
You can open any read-only file in Unix assuming that you have the read permission. Any utility or program that can get access to that file in read mode can open it, which would include programs such as 'more', 'less', 'vi', 'cat', etc. Read-only merely means you can't change it; but you could copy it or look at it.
The Unix file contains which kinds of fields?
Unix is not open source, it is proprietary. Linux is the open-source version of Unix.
There is no the system file. There are many files necessary to create a working Unix system.
Linux is an open system, Unix is not.
The host file in Unix is usually located in the /etc directory.
In Unix, the primary system calls for input and output are read(), write(), open(), close(), and lseek(). The open() call is used to open a file descriptor for reading or writing, while read() and write() perform the actual data transfer between the file descriptor and a buffer in memory. The close() call is used to close the file descriptor, and lseek() allows for repositioning the file pointer within the file. These calls provide a low-level interface for file and device I/O operations.
Unix is a text file, not a web browser. :)
While Microsoft Office is not available on Unix-like systems, you can use other offices suites to open the Excel file format. Consider trying LibreOffice or OpenOffice.org; both are excellent open-source office suites that support most Microsoft Office file formats.
Douglas W. Topham has written: 'A system V guide to UNIX and XENIX' -- subject(s): UNIX System V (Computer file), XENIX (Computer file) 'The first book of UNIX' 'UNIX and XENIX' -- subject(s): UNIX (Computer file), XENIX