testcmd

Documentation

Overview

Package testcmd implements the POSIX test and [ builtin commands.

Usage:

test EXPRESSION
[ EXPRESSION ]

Evaluate a conditional expression and exit with status 0 (true) or 1 (false). The [ form requires a closing ] as the last argument.

Exit codes:

0 — expression evaluates to true
1 — expression evaluates to false
2 — syntax/usage error

Supported operators:

File tests (unary):

-a FILE    FILE exists (deprecated POSIX synonym for -e)
-e FILE    FILE exists
-f FILE    FILE exists and is a regular file
-d FILE    FILE exists and is a directory
-s FILE    FILE exists and has size greater than zero
-r FILE    FILE exists and is readable
-w FILE    FILE exists and is writable
-x FILE    FILE exists and is executable
-h FILE    FILE exists and is a symbolic link
-L FILE    FILE exists and is a symbolic link (same as -h)
-p FILE    FILE exists and is a named pipe (FIFO)

File comparison (binary):

FILE1 -nt FILE2    FILE1 is newer (modification time) than FILE2
FILE1 -ot FILE2    FILE1 is older (modification time) than FILE2

String tests (unary):

-z STRING    length of STRING is zero
-n STRING    length of STRING is non-zero
STRING       STRING is non-empty (equivalent to -n STRING)

String comparison (binary):

S1 = S2     strings are equal
S1 == S2    strings are equal (synonym for =)
S1 != S2    strings are not equal
S1 < S2     S1 sorts before S2 (lexicographic)
S1 > S2     S1 sorts after S2 (lexicographic)

Integer comparison (binary):

N1 -eq N2   integers are equal
N1 -ne N2   integers are not equal
N1 -lt N2   N1 is less than N2
N1 -le N2   N1 is less than or equal to N2
N1 -gt N2   N1 is greater than N2
N1 -ge N2   N1 is greater than or equal to N2

Logical operators:

! EXPR          EXPR is false
EXPR1 -a EXPR2  both EXPR1 and EXPR2 are true
EXPR1 -o EXPR2  either EXPR1 or EXPR2 is true
( EXPR )        grouping (parentheses must be shell-escaped)

Index

• Variables

Variables

var BracketCmd = builtins.Command{
	Name:        "[",
	Description: "evaluate conditional expression",
	MakeFlags:   builtins.NoFlags(runBracket),
}

BracketCmd is the "[" builtin command registration.

var Cmd = builtins.Command{
	Name:        "test",
	Description: "evaluate conditional expression",
	MakeFlags:   builtins.NoFlags(runTest),
}

Cmd is the "test" builtin command registration.