set playground="${HOME}/playground"
set file1=${playground}'/fi$le1'
set file2=${playground}'/file2$'
set file3=${playground}'/f$i$l$e$3$'
set file4=${playground}'/fi\$le4'
mkdir -p ${playground}
touch ${file1}
touch ${file2}
touch ${file3}
touch ${file4}

##</code><code>##

ls -la $HOME/playground
total 8
drwxr-s--- 2 root root 4096 May 22 06:26 .
drwxr-s--- 7 root root 4096 May 22 06:26 ..
-rw-r----- 1 root root    0 May 22 06:26 f$i$l$e$3$
-rw-r----- 1 root root    0 May 22 06:26 fi$le1
-rw-r----- 1 root root    0 May 22 06:26 fi\$le4
-rw-r----- 1 root root    0 May 22 06:26 file2$

##</code><code>##

> touch  $HOME/playground/fi\\\\\$le5
> ls -la  $HOME/playground/
total 8
drwxr-s--- 2 root root 4096 May 22 22:57 .
drwxr-s--- 7 root root 4096 May 22 06:26 ..
-rw-r----- 1 root root    0 May 22 06:26 f$i$l$e$3$
-rw-r----- 1 root root    0 May 22 06:26 fi$le1
-rw-r----- 1 root root    0 May 22 06:26 fi\$le4
-rw-r----- 1 root root    0 May 22 22:57 fi\\$le5
-rw-r----- 1 root root    0 May 22 06:26 file2$

##</code><code>##

drwxr-s--- 2 root root 4096 May 22 22:57 .
drwxr-s--- 7 root root 4096 May 22 06:26 ..
-rw-r----- 1 root root    0 May 22 06:26 fUNSPECIFIED$iUNSPECIFIED$lUNSPECIFIED$eUNSPECIFIED$3UNSPECIFIED$
-rw-r----- 1 root root    0 May 22 06:26 fiUNSPECIFIED$le1
-rw-r----- 1 root root    0 May 22 06:26 fi\UNSPECIFIED$le4
-rw-r----- 1 root root    0 May 22 22:57 fi\\UNSPECIFIED$le5
-rw-r----- 1 root root    0 May 22 06:26 file2UNSPECIFIED$