this is one:
ls -l . | egrep -c '^-'
ls -1 | wc -l
Which means: ls: list files in dir
-1: (that’s a ONE) only one entry per line. Change it to -1a if you want hidden files too
| : pipe output onto…
-l: count lines.
Source: Count number of files within a directory in Linux (not using wc) – Stack Overflow