whereis & which & type

Question 1

whereis

Answer 1

whereis locates the binary, source and manual files for the specified command names.

Question 2

whereis

• b, search only for binaries
• B <dirs>, define binaries lookup path</dirs>
• m, search only for manuals and infos
• M <dirs>, define manual and infos lookup path</dirs>
• s, search only for sources
• S <dirs>, define sources lookup path</dirs>

Answer 2

• f, terminate <dirs> argument list</dirs>
• u, search for unusual entries
• l, output effective lookup paths

Question 3

which

Answer 3

which returns the pathnames of the files (or links) which would be executed in the current environment, had its arguments been given as commands in a strictly POSIX-conformant shell.

Question 4

which -a filename

Answer 4

-a, print all matching pathnames of each argument.

Question 5

type

Answer 5

Display information about command type. For each NAME, indicate how it would be interpreted if used as a command name.

Question 6

type

• a
• f
• P
• p
• t

Answer 6

• a, Display all locations containing an executable named NAME.
• f, Suppress shell function lookup.
• P, Force a PATH search for each NAME.
• p, Returns either the name of the disk file that would be executed, or nothing if type -t NAME would not return ‘file’
• t, Output a single word which is one of: alias, keyword, function, builtin, file, or ‘’ for NAME.