chapter: Command-Line Options

Author: pmarinov

index.ptree

@@ -121,6 +121,7 @@ pages/bibliography.poly.pm
   pages/parsing_pathnames.poly.pm
   pages/exit_codes.poly.pm
   pages/io_redirection_de.poly.pm
+  pages/command_line_opt.poly.pm
 }
 
 }

pages/command_line_opt.poly.pm

@@ -0,0 +1,156 @@
+#lang pollen
+
+◊page-init{}
+◊define-meta[page-title]{Command-Line Options}
+◊define-meta[page-description]{Command-Line Options}
+
+◊section{Standard Command-Line Options}
+
+Over time, there has evolved a loose standard for the meanings of
+command-line option flags. The GNU utilities conform more closely to
+this "standard" than older UNIX utilities.
+
+Traditionally, UNIX command-line options consist of a dash, followed
+by one or more lowercase letters. The GNU utilities added a
+double-dash, followed by a complete word or compound word.
+
+The two most widely-accepted options are:
+
+◊definition-block[#:type "code"]{
+
+◊definition-entry[#:name "-h, --help"]{
+Help
+
+Give usage message and exit.
+
+}
+
+◊definition-entry[#:name "-v, --version"]{
+Version
+
+Show program version and exit.
+
+}
+
+}
+
+Other common options are:
+
+◊definition-block[#:type "code"]{
+
+◊definition-entry[#:name "-a, --all"]{
+All
+
+Show all information or operate on all arguments.
+
+}
+
+◊definition-entry[#:name "-l, --list"]{
+List
+
+List files or arguments without taking other action.
+
+}
+
+◊definition-entry[#:name "-o"]{
+Output filename
+
+}
+
+◊definition-entry[#:name "-q, --quiet"]{
+Quiet
+
+Suppress stdout.
+
+}
+
+◊definition-entry[#:name "-r, -R, --recursive"]{
+Recursive
+
+Operate recursively (down directory tree).
+
+}
+
+◊definition-entry[#:name "-v, --verbose"]{
+Verbose
+
+Output additional information to stdout or stderr.
+
+}
+
+◊definition-entry[#:name "-z, --compress"]{
+Compress
+
+Apply compression (usually ◊command{gzip}).
+
+}
+
+}
+
+However:
+
+◊definition-block[#:type "code"]{
+
+◊definition-entry[#:name "In tar: -f, --file"]{
+File
+
+Filename follows.
+
+}
+
+◊definition-entry[#:name "In cp, mv, rm:: -f, --force"]{
+Force
+
+Force overwrite of target file(s).
+
+}
+
+}
+
+Caution: Many UNIX and Linux utilities deviate from this "standard,"
+so it is dangerous to assume that a given option will behave in a
+standard way. Always check the man page for the command in question
+when in doubt.
+
+A complete table of recommended options for the GNU utilities is
+available at the GNU standards page.
+
+See: ◊url[#:link "https://www.gnu.org/prep/standards/"]{}
+
+◊section{Bash Command-Line Options}
+
+Bash itself has a number of command-line options. Here are some of the
+more useful ones.
+
+◊definition-block[#:type "code"]{
+
+◊definition-entry[#:name "-c"]{
+Read commands from the following string and assign any arguments to
+the positional parameters.
+
+◊example{
+bash$ bash -c 'set a b c d; IFS="+-;"; echo "$*"'
+a+b+c+d
+}
+
+}
+
+◊definition-entry[#:name "-r, --restricted"]{
+Runs the shell, or a script, in restricted mode.
+
+}
+
+◊definition-entry[#:name "--posix"]{
+Forces Bash to conform to POSIX mode.
+
+}
+
+◊definition-entry[#:name "--"]{
+End of options.
+
+Anything further on the command line is an argument,
+not an option.
+
+}
+
+}