E.X:
file somefile.x

output is [...ASCII text, with very long lines]

I want to know how many bytes per line is very long line.
Is the number depend on the different computer or system setting ?
or all the linux have a same define to "very long line".

ps:sorry about my english. I hope you can understand it.

A long line is defined by the number of characters on the display device. If you have a monitor that can display 80 characters per line, then a line longer than 80 characters will scroll to the next line below. Very long lines can be difficult to read.
Imagine how it would look if viewed on a phone or other smaller resolution display device.

There is no limit to the number of charcaters in an ASCII file, the file can be as large as you want, limited by the
space on your hard drive.

The number of bytes per line depends on the length of your line, so a single ASCII character like "A" is one byte,
however when stored as a file may occupy slightly more space depending on the filesystem and number of inodes, hope that helps.

1 members found this post helpful.

If you have on mind exactly command "file" than you can look into source of this program, and for example in Ubuntu, you see in file "ascmagic.c" that this is defined as 300 bytes. But it depends who compiled that file as everybody / organization can change it.

2 members found this post helpful.

I got it ,THANKS.

If you see that "very long lines" bit you might suspect that the file is not really ascii text, or is but in a special format.
I run into data files daily that are reported that way. (ISAM, DBC txt files)

Take that report with a grain of salt. It is sometimes exactly correct.