If Found...

• If the device was lost or stolen, the requirement to return the device does not apply. However, if the lost device is found, you should return it by using the pre-addressed pre-paid return label included with the replacement device.
• First 'needle' found at: 14 second 'needle' found at: 44 'haystack' also found at: 30 Period found at: 51 There are two prepositions in this haystack with needles. Complexity Unspecified, but generally up to linear in length -pos times the length of the sequence to match (worst case).

If you found the RSA SecurID token within your company, you should contact your company’s Information Technology department. Your IT department will be able to locate the owner and return the token to them. If no one in your company uses these tokens, or if you found the token in a public place (such as an airport or a parking lot), you.

The If Found Lock Screen app for the iPhone, iPad, and iPod touch allows you to add messages to your Lock Screen wallpaper. Most people use it to add their contact information to the Lock Screen, so that if their iOS device is ever lost, whoever finds it can easily get in touch with them.

You can add as many messages as you need. Just drag and drop to move the text to any location. Double tap to edit the text. You can enter any text that you want, as well as change the font, color, size, and alignment of the text. You can also change the color, transparency, and width of the background color bar behind the text.

You can choose any photo from your Photo Library, or pick from the free wallpapers that come with the app. Move the photo by dragging, and resize it by pinching. Double tap the photo to choose a different photo.

• For the iPhone, iPad, and iPod touch.
• Add as many text areas as you need. Enter any text that you want.
• Easily edit the text, and its font, color, size, and alignment.
• Set the color, transparency, and width of the background color bar behind the text.
• Choose photos from your Photo Library or free wallpapers.
• Optimized for the retina display.

Conditionally perform a command.

IF will only parse numbers when one of (EQU, NEQ, LSS, LEQ, GTR, GEQ) is used.
The comparison operator always results in a string comparison.

ERRORLEVEL

There are two different methods of checking an errorlevel, the first syntax ( IF ERRORLEVEL ... ) provides compatibility with ancient batch files from the days of Windows 95.
The second method is to use the %ERRORLEVEL% variable providing compatibility with Windows 2000 or newer.

IF ERRORLEVEL n statements should be read as IF Errorlevel>=number
i.e.
IF ERRORLEVEL 0 will return TRUE whether the errorlevel is 0, 1 or 5 or 64
IF ERRORLEVEL 1 will return TRUE whether the errorlevel is 1 or 5 or 64
IF NOT ERRORLEVEL 1 means if ERRORLEVEL is less than 1 (Zero or negative).
This is not very readable or user friendly and does not easily account for negative error numbers.

Using the %ERRORLEVEL% variable is a more logical method of checking Errorlevels:

IF %ERRORLEVEL% NEQ 0 Echo An error was found
IF %ERRORLEVEL% EQU 0 Echo No error found
IF %ERRORLEVEL% EQU 0 (Echo No error found) ELSE (Echo An error was found)
IF %ERRORLEVEL% EQU 0 Echo No error found || Echo An error was found

This allows you to trap errors that can be negative numbers, you can also test for specific errors:
IF %ERRORLEVEL% EQU 64 ...

To deliberately raise an ERRORLEVEL in a batch script use the EXIT /B command.

It is possible (though not a good idea) to create a string variable called %ERRORLEVEL% (user variable)
if present such a variable will prevent the real ERRORLEVEL (a system variable) from being used by commands such as ECHO and IF.

Test if a variable is empty

To test for the existence of a command line parameter - use empty brackets like this

IF [%1][] ECHO Value Missing
or
IF [%1] EQU [] ECHO Value Missing
When comparing against a variable that may be empty, we include a pair of brackets [ ] so that if the variable does happen to be empty the IF command still has something to compare: IF [] EQU [] will return True.

You can in fact use almost any character for this a '~' or curly brackets, { } or even the number 4, but square brackets tend to be chosen because they don't have any special meaning.
When working with filenames/paths you should always surround them with quotes, if %_myvar% contains 'C:Some Path' then your comparison becomes IF ['C:Some Path'] EQU []
if %_myvar% could contain empty quotes, ' then your comparison should become IF [%_myvar%] EQU [']
if %_myvar% will never contain quotes, then you can use quotes in place of the brackets IF '%_myvar%' EQU '
However with this pattern if %_myvar% does unexpectedly contain quotes, you will get IF 'C:Some Path' EQU ' those doubled quotes, while not officially documented as an escape will still mess up the comparison.

Test if a variable is NULL

In the case of a variable that might be NULL - a null variable will remove the variable definition altogether, so testing for a NULL becomes:
IF NOT DEFINED _example ECHO Value Missing
IF DEFINED will return true if the variable contains any value (even if the value is just a space)

To test for the existence of a user variable use SETVariableName, or IF DEFINED VariableName

Test the existence of files and folders

IF EXIST filename Will detect the existence of a file or a folder.

The script empty.cmd will show if the folder is empty or not (this is not case sensitive).

Parenthesis

Parenthesis can be used to split commands across multiple lines. This enables writing more complex IF… ELSE… commands:

When combining an ELSE statement with parentheses, always put the opening parenthesis on the same line as ELSE.
) ELSE ( This is because CMD does a rather primitive one-line-at-a-time parsing of the command.

When using parentheses the CMD shell will expand [read] all the variables at the beginning of the code block and use those values even if the variables value has just been changed. Turning on DelayedExpansion will force the shell to read variables at the start of every line.

Pipes

When piping commands, the expression is evaluated from left to right, so

IF SomeConditionCommand1 | Command2is equivalent to:

(IF SomeConditionCommand1 ) | Command2
The pipe is always created and Command2 is always run, regardless whether SomeCondition is TRUE or FALSE

You can use brackets and conditionals around the command with this syntax:

IF SomeCondition (Command1 | Command2)
If the condition is met then Command1 will run, and its output will be piped to Command2.

The IF command will interpret brackets around a condition as just another character to compare (like # or @) for example:
IF (%_var1%(demo Echo the variable _var1 contains the text demo

Placing an IF command on the right hand side of a pipe is also possible but the CMD shell is buggy in this area and can swallow one of the delimiter characters causing unexpected results.
A simple example that does work:

Echo Y | IF redblue del *.log

Chaining IF commands (AND).

The only logical operator directly supported by IF is NOT, so to perform an AND requires chaining multiple IF statements:

If either condition is true (OR)

This can be tested using a temporary variable:

Set '_tempvar='
If SomeCondition Set _tempvar=1
If SomeOtherCondition Set _tempvar=1
if %_tempvar% EQU 1 Command_to_run_if_either_is_true

Delimiters

If the string being compared by an IF command includes delimiters such as [Space] or [Comma], then either the delimiters must be escaped with a caret ^ or the whole string must be 'quoted'.
This is so that the IF statement will treat the string as a single item and not as several separate strings.

Test Numeric values

IF only parses numbers when one of the compare-op operators (EQU, NEQ, LSS, LEQ, GTR, GEQ) is used.
The comparison operator always results in a string comparison.

This is an important difference because if you compare numbers as strings it can lead to unexpected results: '2' will be greater than '19' and '026' will be less than '10'.

Correct numeric comparison:
IF 2 GEQ 15 echo 'bigger'

Using parentheses or quotes will force a string comparison:
IF (2) GEQ (15) echo 'bigger'
IF '2' GEQ '15' echo 'bigger'

If Found C++

This behaviour is exactly opposite to the SET /a command where quotes are required.

IF should work within the full range of 32 bit signed integer numbers (-2,147,483,648 through 2,147,483,647)

C:> if 2147483646 GEQ 2147483647 (Echo Larger) Else (Echo Smaller)
Smaller ⇨ correct

C:> if 2147483647 GEQ 2147483648 (Echo Larger) Else (Echo Smaller)
Larger ⇨ wrong due to overflow

C:> if -2147483649 GEQ -2147483648 (Echo Larger) Else (Echo Smaller)
Larger ⇨ wrong due to overflow

You can perform a string comparison on very long numbers, but this will only work as expected when the numbers are exactly the same length:

C:> if '2147483647' GEQ '2147483648' (Echo Larger) Else (Echo Smaller)
Smaller ⇨ correct

Wildcards

Wildcards are not supported by IF, so %COMPUTERNAME%SS6* will not match SS64
A workaround is to retrieve the substring and compare just those characters:
SET _prefix=%COMPUTERNAME:~0,3%
IF %_prefix%SS6 GOTO they_matched

If Command Extensions are disabled IF will only support direct comparisons: IF , IF EXIST, IF ERRORLEVEL
also the system variable CMDEXTVERSION will be disabled.

IF does not, by itself, set or clear the Errorlevel.

Examples:

IF is an internal command.

You see things; and you say 'Why?' But I dream things that never were; and I say 'why not?' ~ George Bernard Shaw

Related:

Using parentheses to group and expand expressions.
Conditional execution syntax (AND / OR)
SET - Display or Edit environment variables.
ECHO - Display message on screen.
EXIT - Set a specific ERRORLEVEL.
IFMEMBER - group member (Resource kit).
SC - Is a Service running (Resource kit).
Powershell: if - Conditionally perform a command.
Equivalent bash command (Linux): if - Conditionally perform a command.

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