sh

func Command ¶

func Command(args ...string) (result []byte, err error)

Command execute a simple command or display information about commands.

Usage: command [-pVv] command [arg ...]

Runs COMMAND with ARGS suppressing shell function lookup, or display information about the specified COMMANDs. Can be used to invoke commands on disk when a function with the same name exists.

Options:

-p    use a default value for PATH that is guaranteed to find all of
      the standard utilities (Ignored and always true)
-v    print a description of COMMAND similar to the `type' builtin
-V    print a more verbose description of each COMMAND (Not implemented)

Exit Status:

Returns exit status of COMMAND, or failure if COMMAND is not found.

func Printf ¶

func Printf(format string, args ...any) (result string, err error)

Printf formats and prints ARGUMENTS under control of the FORMAT.

Usage: printf format [arguments]

FORMAT is a character string which contains three types of objects: plain characters, which are simply copied to standard output; character escape sequences, which are converted and copied to the standard output; and format specifications, each of which causes printing of the next successive argument.

The format is re-used as necessary to consume all of the arguments. If there are fewer arguments than the format requires, extra format specifications behave as if a zero value or null string, as appropriate, had been supplied.

Exit Status:

Returns success unless an invalid option is given or a write or assignment error occurs.

func Subst ¶

func Subst(str, pattern string) (result string)

Subst does shell variable substitution implemented: #, ##, %, %%, ^, ^^, ',', ',,', :, /

func Test ¶

func Test(args ...string) (result bool)

Test evaluate conditional expression.

Usage: test [expr]

Exits with a status of 0 (true) or 1 (false) depending on the evaluation of EXPR. Expressions may be unary or binary. Unary expressions are often used to examine the status of a file. There are string operators and numeric comparison operators as well.

The behavior of test depends on the number of arguments. Read the bash manual page for the complete specification.

File operators:

-a FILE        True if file exists.
-b FILE        True if file is block special.
-c FILE        True if file is character special.
-d FILE        True if file is a directory.
-e FILE        True if file exists.
-f FILE        True if file exists and is a regular file.
-g FILE        True if file is set-group-id.
-h FILE        True if file is a symbolic link.
-L FILE        True if file is a symbolic link.
-k FILE        True if file has its `sticky' bit set.
-p FILE        True if file is a named pipe.
-r FILE        True if file is readable by you.
-S FILE        True if file is a socket.
-t FD          True if FD is opened on a terminal.
-u FILE        True if the file is set-user-id.
-w FILE        True if the file is writable by you.
-x FILE        True if the file is executable by you.
-O FILE        True if the file is effectively owned by you.
-G FILE        True if the file is effectively owned by your group.
-N FILE        True if the file has been modified since it was last read.

FILE1 -nt FILE2  True if file1 is newer than file2 (according to
                 modification date).

FILE1 -ot FILE2  True if file1 is older than file2.

FILE1 -ef FILE2  True if file1 is a hard link to file2.

String operators:

-z STRING      True if string is empty.

-n STRING
   STRING      True if string is not empty.

STRING1 = STRING2
               True if the strings are equal.
               True if the strings are not equal.
STRING1 < STRING2
               True if STRING1 sorts before STRING2 lexicographically.
STRING1 > STRING2
               True if STRING1 sorts after STRING2 lexicographically.

Other operators:

  -o OPTION      True if the shell option OPTION is enabled.
  -v VAR         True if the shell variable VAR is set.
  -R VAR         True if the shell variable VAR is set and is a name
                 reference.
  ! EXPR         True if expr is false.
  EXPR1 -a EXPR2 True if both expr1 AND expr2 are true.
  EXPR1 -o EXPR2 True if either expr1 OR expr2 is true.

  arg1 OP arg2   Arithmetic tests.  OP is one of -eq, -ne,
                 -lt, -le, -gt, or -ge.

Arithmetic binary operators return true if ARG1 is equal, not-equal,
less-than, less-than-or-equal, greater-than, or greater-than-or-equal
than ARG2.

Exit Status:

Returns success if EXPR evaluates to true; fails if EXPR evaluates to false or an invalid argument is given.