*sum: update pages to make them consistent (#14923)

* *sum: update pages to make them consistent

* shasum: remove redundant option

* shasum: update page

pages/common/shasum.md

@@ -7,13 +7,9 @@
 
 `shasum {{path/to/file1 path/to/file2 ...}}`
 
-- Calculate the SHA256 checksum for one or more files:
+- Calculate the SHA checksum for one or more files with the specified algorithm:
 
-`shasum --algorithm 256 {{path/to/file1 path/to/file2 ...}}`
-
-- Calculate the SHA512 checksum for one or more files:
-
-`shasum --algorithm 512 {{path/to/file1 path/to/file2 ...}}`
+`shasum --algorithm {{1|224|256|384|512|512224|512256}} {{path/to/file1 path/to/file2 ...}}`
 
 - Calculate a SHA1 checksum from `stdin`:
 
@@ -23,7 +19,7 @@
 
 `shasum --algorithm 256 {{path/to/file1 path/to/file2 ...}} > {{path/to/file.sha256}}`
 
-- Read a file of SHA1 sums and filenames and verify all files have matching checksums:
+- Read a file of SHA checksums and filenames and verify all files have matching checksums (the algorithm will be automatically detected):
 
 `shasum --check {{path/to/file}}`
 
@@ -34,3 +30,7 @@
 - Only show a message when verification fails, ignoring missing files:
 
 `shasum --ignore-missing --check --quiet {{path/to/file}}`
+
+- Check a known SHA checksum of a file:
+
+`echo {{known_sha_checksum_of_the_file}} {{path/to/file}} | shasum --check`