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Delete a file or folder

hdel x     hdel[x]

Where x is a file symbol atom, deletes the file or folder and returns x.

q)hdel`:test.txt   / delete test.txt in current working directory
q)hdel`:test.txt   / should generate an error
'test.txt: No such file or directory

hdel can delete folders only if empty.

To delete a folder and its contents, recursively

​/diR gets recursive dir listing​
q)diR:{$[11h=type d:key x;raze x,.z.s each` sv/:x,/:d;d]}
​/hide power behind nuke​
q)​nuke:hdel​ ​each​ ​​desc diR​@​ / desc sort!​

For a general visitor pattern with hdel

​q)visitNode:{if[11h=type d:key y;.z.s[x]each` sv/:y,/:d;];x y}

Unlike Linux, Windows doesn’t allow one to overwrite files which are memory mapped, and it takes some mS after unmapping for that to become possible.

File system