But if you're going to enumerate alternatives like [[...]], you must inform also that the right-hand-side must be quoted. These hold information Bash can readily access, such as your username, locale, the number of commands your history file can hold, your default editor, and lots more. (From bash man page: "Any part of the pattern may be quoted to force it to be matched as a string."). In this tutorial, we shall learn syntax of OR operator, and how to use Bash OR with IF statement, Bash OR with while or for loop. The [and [[evaluate conditional expression. The syntax of the if-else statement in bash is: if [condition] then //if block code else // else block code fi. The boolean expression returns true if the variable is set and false if the variable is not set. How do I split a string on a delimiter in Bash? I am doing some bash script and now I got one variable call source and one array called samples, like this: as I want to expand the number of sources (and each source has its own samples) I tried to add some arguments to do this. Asking for help, clarification, or responding to other answers. Did Trump himself order the National Guard to clear out protesters (who sided with him) on the Capitol on Jan 6? You just learned how to determine if a bash variable is empty using various methods. So many are bitten by this bug: The correct test for 10 being arithmetically less than 2 is this: In comments, there is a question about the technical reason why using the integer -eq on strings returns true for strings that are not the same: The reason is that Bash is untyped. :-(, @DJCrashdummy, ...huh, I assumed you'd withdrawn it yourself. The"yes" is interpreted as a integer 0; the comparison is True if the other integer is either … Bash variables are untyped so [[ "yes" -eq "no" ]] is equivalent to [[ "yes" -eq 0 ]] or [[ "yes" -eq "any_noninteger_string" ]]-- All True. You need to pass the -z or -n option to the test command or to the if command or use conditional expression.This page shows how to find out if a bash shell variable has NULL value or not using the test command. Stack Overflow for Teams is a private, secure spot for you and and branches based on whether it is True (0) or False (not 0). If you are using […] (or single brackets) or [[…]] (or double brackets), or test you can use one of -eq, -ne, -lt, -le, -gt, or -ge as an arithmetic comparison. Each operator returns true (0) if the condition is met and false (1) if the condition is not met. Is it simply that = and == are only used when the variables contain numbers? How do I iterate over a range of numbers defined by variables in Bash? Stack Overflow for Teams is a private, secure spot for you and The if test condition-true construct is the exact equivalent of if [ condition-true ]. @Systemd authors: can you please make "building a Linux shell that doesn't suck" your next project? Does there exist a universal formula of first-order logic that is satisfiable only by structures with infinite domains? Well put! When you test a variable/string in bash without specifying the type of test ( -n or -z ), it will default to a -n (nonzero length string) test. If you use ((…)), you are testing arithmetic equality with == as in C: (Note: 0 means true in the Unix sense and a failed test results in a non-zero number.). It seems that you are looking to parse commandline arguments into your bash script. THANKS @Alex, I ran into issues with this when the variable on the left was an empty string. As it happens, the left bracket, [ , is a token [1] which invokes the test command. Writing setup, CI and deployment flows means a bit of the old bash scripting. rev 2021.1.8.38287, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide. expr1-a expr2: Returns true if … From the bash variables tutorial, you know that $ (command) syntax is used for command substitution and it gives you the output of the command. They do not make your function return those values, to do that use the return command, and integer values corresponding to success (0) or failure (anything other than 0). By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Your options are double parentheses, double brackets, single brackets, or test. AND logical operator combines two or more simple or compound conditions and forms a compound condition. For [...] that is safe for string equality. Syntax of if statement Bash officially gets my vote for beeing the most outdated yet still used command language. Environment Variables. Please note that the following is bash specific syntax and it will not work with BourneShell: When comparing strings in Bash you can use the following operators: string1 = string2 and string1 == string2 - The equality operator returns true if the operands are equal. I much more appreciate these types of corrections and explanations though than Mr Vazquez-Abrams arrogant comments just pointing out that someone is wrong without bothering to explain or clarify. I tried this: but when I ran my script source countries.sh country it didn't work. If the condition evaluates to true, commands are executed. Comparison Operators # Comparison operators are operators that compare values and return true or false. Expansion of variables inside single quotes in a command in Bash, Check number of arguments passed to a Bash script. If it is not true then don't perform those actions. However, [[is bash’s improvement to the [command. Do not leave out the double quotes above.). Bash Script File Bash If Statement with Bash, Bash Introduction, Bash Scripting, Bash Shell, History of Bash, Features of Bash, Filesystem and File Permissions, Relative vs Absolute Path, Hello World Bash Script, Bash Variables, Bash Functions, Bash Conditional Statements etc. Bash has a large set of logical operators that can be used in conditional expressions. For bash (but not ksh93 nor zsh), for variables of type associative array, that would not report them as set unless their element of key "0" has been set. Last note: Many of the Bash specific extensions to the Test Constructs are not POSIX and therefore may fail in other shells. The -eq causes the strings to be interpreted as integers if possible including base conversion: And 0 if Bash thinks it is just a string: So [[ "yes" -eq "no" ]] is equivalent to [[ 0 -eq 0 ]]. There are three types of operators: file, numeric, and non-numeric operators. The Linux environment variables, Bash environment variables, and Shell specials variables allow us to pass information between commands and subprocesses, or control some of the shell behavior. Why is this code the same as the proposed and accepted solution? if [ ! Why do password requirements exist while limiting the upper character count? Today, test is builtin to bash and is commonly known by its one character alias [(or an executable to use in shells lacking it, as dolmen notes): Defining a variable with or without export, How to concatenate string variables in Bash. In the example below, on each iteration, the current value of the variable i is printed and incremented by one. Well put! bash if -f : Check if file exists and is a regular file if statement when used with option f, returns true if the length of the string is zero. If you're writing a #!/bin/bash script then I recommend using [[ instead. Why do massive stars not undergo a helium flash. Then, a variable can be set to an empty string or it can be unset. The proper method is for brackets to contain spacing within, and operators to contain spacing around. if the tools were cryptic to use, hard to understand, and generally out of reach of the great unwashed without the inside knowledge handed down from master to padwan, it would ensure that there would always be work for those "in the know". This tutorial describes how to compare strings in Bash. The -eq forces integer comparison. The output from this script returns zero exit status as both the variables have same number. test: The command to perform a comparison; 1:The first element you are going to compare.In this example, it's the number 1 but it could be any number, or a string within quotes.-eq: The method of comparison.In this case, you are testing whether one value equals another. If you make a magic weapon your pact weapon, can you still summon other weapons? What's the difference between [ and [[ in Bash? This is a synonym for the test command/builtin. Bash uses environment variables to define and record the properties of the environment it creates when it launches. Terminal Output Two strings are equal. It is easy to find whether or not a variable is empty in Bash under Linux or … Example 1 – Check if Variable is Set using -v. In this example, we use [[ -v variableName ]] boolean expression to check if variables a and b are set with the help of bash if else statement. Colleagues don't congratulate me or cheer me on when I do good work. Bash AND Logical Operator Under Logical operators, Bash provides logical AND operator that performs boolean AND operation. The IF logical operator is commonly used in programming languages to control flow. echo 'even' –» it prints “even” to your screen else –» and this is the other “flag” that tells bash that if the statement above was not true (false) , then execute the command here instead. The closing right bracket, ] , in an if/test should not therefore be strictly necessary, however newer versions of Bash require it. How do I pass command line arguments to a Node.js program? Looping through the content of a file in Bash, How to echo shell commands as they are executed. your coworkers to find and share information. Here in bash, the two statements yielding "yes" are pattern matching, other three are string equality: Thanks for contributing an answer to Stack Overflow! Does healing an unconscious, dying player character restore only up to 1 hp unless they have been stabilised? command ] doesn't execute command; it treats command as a string and treats it as true because it has a non-zero length. Otherwise, if the condition evaluates to false, the loop is terminated, and the program control will be passed to the command that follows. Syntax is just so non intuitive it hurts. Bash Check if Variable is Set with Bash, Bash Introduction, Bash Scripting, Bash Shell, History of Bash, Features of Bash, Filesystem and File Permissions, Relative vs Absolute Path, Hello World Bash Script, Bash Variables, Bash Functions, Bash Conditional Statements etc. shell functions and argument passing issue. Basically all bash variables are just strings. Please note that the following is bash specific syntax and it will not work with BourneShell: The bash scripting language uses this convention to mark the end of a complex expression, such as an if statement or case statement. It's the other way around: = and == are for string comparisons, -eq is for numeric ones. In this article, i’ll show how to test if a variable exists or not, if it is empty or not and if it is set to True. How to mkdir only if a directory does not already exist? if the tools were cryptic to use, hard to understand, and generally out of reach of the great unwashed without the inside knowledge handed down from master to padwan, it would ensure that there would always be work for those "in the know". It's better to use the POSIX =. Since the two strings are equal, the condition returns true and the if block executes. How do I set a variable to the output of a command in Bash? Rhythm notation syncopation over the third beat. The important factor is the spacing within the brackets. The most basic form of the ifcontrol structure tests for a condition and then executes a list of program statements if the condition is true. When/how to use “==” or “-eq” operator in test? How do I split a string on a delimiter in Bash? What is the term for diagonal bars which are making rectangular frame more rigid? Why is "I can't get any satisfaction" a double-negative too, according to Steven Pinker? Can an exiting US president curtail access to Air Force One from the new president? How to write a shell script to run a Makefile? Guys: Several answers show dangerous examples. Is there a difference between “=” and “==” in Bash? Could the US military legally refuse to follow a legal, but unethical order? if [ ! In Jinja2 templates, it is often a good practice to test if a variable exists and what value does it carry. This allows one to think of a variable that is unset as false and variable set to any value as true. Oh yes, you are ofcourse right. Why would the ages on a 1877 Marriage Certificate be so wrong? To learn more, see our tips on writing great answers. If value equals 1. Save the code in a file and run it from the command line: bash test.sh. exit status: 0 Both integers are equal . +1 for actually trying something and good formatting of question. Making statements based on opinion; back them up with references or personal experience. Also, I'm pretty sure you don't want to return failure for the first line that doesn't match, just if no line matched: While you can do [[ 1 == 1 ]] or [[ $(( 1+1 )) == 2 ]] it is testing the string equality — not the arithmetic equality. The syntax for the simplest form is:Here, 1. Bash check if a string contains a substring . Since the two strings are equal, the condition returns true and the if block executes. Really no place for it in 2016+. The first example is one of the most basic examples, if true. How to check if a string contains a substring in Bash. However, we can define the shell variable having value as 0 (“ False “) or 1 (“ True “) as per our needs. (Side note: Quote those variable expansions! Bash doesn't have any special values for True or False, so the only "false" value is 0. Now, let us take different string values, and check if the two strings are equal. good luck. @masi sometimes i think the original intent of unix was "job security through obscurity". little has changed. OR operator returns true if any of the operands is true, else it returns false. Comparison Operators # Comparison operators are operators that compare values and return true or false. There are no Booleans in Bash. There are several useful tests that you can make using Jinja2 builtin tests and filers.. This tutorial describes how to compare strings in Bash. Can someone please explain the difference between =, == and -eq in shell scripting? The boolean expression returns true if the variable is set and false if the variable is not set. This is a synonym for the test command/builtin. It is a conditional statement that allows a test before performing another statement. What is the term for diagonal bars which are making rectangular frame more rigid? site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. What factors promote honey's crystallisation? Why would the ages on a 1877 Marriage Certificate be so wrong? true and false are commands that exit with success and failure exit codes, respectively. I came across the following which I think will assist you in parsing the arguments: http://rsalveti.wordpress.com/2007/04/03/bash-parsing-arguments-with-getopts/, ./script.sh -t test -r server -p password -v. Thanks for contributing an answer to Stack Overflow! Although the tests above returned only 0 or 1 values, commands may return other values. Bash IF. How can I declare and use Boolean variables in a shell script? (It's possible this refers to an indirect reference, as described in Parameter expansion in bash.)! if [ $value -eq 1 ] then … By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. You can quickly test for null or empty variables in a Bash shell script. Join Stack Overflow to learn, share knowledge, and build your career. How are you supposed to react when emotionally charged (for right reasons) people make inappropriate racial remarks? I have searched for this recently myself. Quantum harmonic oscillator, zero-point energy, and the quantum number n. How to display all trigonometric function plots in a table? In this article, i’ll show how to test if a variable exists or not, if it is empty or not and if it is set to True. but you've been thinking about this for a while. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. In Jinja2 templates, it is often a good practice to test if a variable exists and what value does it carry. Okay thats it. Bash check if a string contains a substring . However, [[is bash’s improvement to the [command. [ is a synonym for the test command – Keith Thompson Jan 14 '12 at 9:36 Now, let us take different string values, and check if the two strings are equal. Is there a resource anywhere that lists every spell and the classes that can use them? How do I iterate over a range of numbers defined by variables in Bash? this philosophy is evident in the whole "RFC" construct, and flowery language used in man documents, which whilst technically telling you how to use the tools, really just were there to fulfill a requirement of having documented the tools. You need to pass the -z or -n option to the test command or to the if command or use conditional expression.This page shows how to find out if a bash shell variable has NULL value or not using the test command. What am I doing wrong? In some instances different combinations work; however, the following is intended to be a universal example. In bash the two are equivalent, and in plain sh = is the only one guaranteed to work. Why is "I can't get any satisfaction" a double-negative too, according to Steven Pinker? Bash IF statement is used for conditional branching in the sequential flow of execution of statements.. We shall learn about the syntax of if statement and get a thorough understanding of it with the help of examples. You use it to check the state of a value, whether it is equal to another or not; or whether it is set or not, for example. In the example below, on each iteration, the current value of the variable i is printed and incremented by one. [ is a synonym for the test command – Keith Thompson Jan 14 '12 at 9:36 OP's example [ $a == $b ] specifically used unquoted variable substitution (as of Oct '17 edit). If the condition evaluates to true, the if block code is executed, and if the condition evaluates to false then the else block code is executed. Bash Script File How can I check if a directory exists in a Bash shell script? Does healing an unconscious, dying player character restore only up to 1 hp unless they have been stabilised? then –» this is the “flag” that tells bash that if the statement above was true, then execute the commands from here. How can I pass arguments to a batch file? Please consider editing your question to include required outputs and any error messages you're getting. Is there any difference between the following? site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. The condition $ (whoami) = 'root' will be true only if you are logged in as the root user. When a microwave oven stops, why are unpopped kernels very hot and popped kernels not hot? if arguments is equal to this string, define a variable like this string, Podcast 302: Programming in PowerPoint can teach you a few things, How to equal a variable with a variable attached to another variable in Shell script. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Example 1 – Check if Variable is Set using -v In this example, we use [ [ -v variableName ]] boolean expression to check if variables a and b are set with the help of bash if else statement. eq being a numeric comparison of course. If not quoted, it is a pattern match! Set the variable if it isn't already set, or if it's set to NULL (\0) or the empty string: If the condition evaluates to true, commands are executed. The bash if command is a compound command that tests the return value of a test or command ($?) Bash OR logical operator can be used to form compound boolean expressions for conditional statements or looping statements. Also, note the whitespace around = or ==: it’s required. I'll throw money at you. It depends on what you mean by false. neighbouring pixels : next smaller and bigger perimeter. Can 1 kilogram of radioactive material with half life of 5 years just decay in the next minute? If follows the format below: if [ ] @masi sometimes i think the original intent of unix was "job security through obscurity". Basically, it was an objection about unquoted expansions inside, @CharlesDuffy no, it's not the sole reason: beside the fact that i don't like bash-isms, ksh-isms etc. So -eq produces the result probably expected that the integer value of 1+1 is equal to 2 even though the right-hand side is a string and has a trailing space: While a string comparison of the same picks up the trailing space and therefore the string comparison fails: And a mistaken string comparison can produce a completely wrong answer. Is it possible to edit data inside unencrypted MSSQL Server backup file (*.bak) without SSMS? Is there an English adjective which means "asks questions frequently"? rev 2021.1.8.38287, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide, @DJCrashdummy, ...the link you show points out correctly that quotes are sometimes needed on the, @CharlesDuffy unfortunately i have no idea what are you referring to, because my comment seems to be deleted and i can't remember because it has been quite a time. -eq is in the same family as -lt, -le, -gt, -ge, and -ne, if that helps you remember which is which. To learn more, see our tips on writing great answers. Double quotes are no longer required around $a, for one: It depends on the Test Construct around the operator. command ] doesn't execute command; it treats command as a string and treats it as true because it has a non-zero length. Bash Cheatsheet: check if environment variables are set or file/symlinks exists + more A bash scripting cheat sheet for developers who just want to get by. Following example proves the same. Does any Āstika text mention Gunas association with the Adharmic cults? There are several useful tests that you can make using Jinja2 builtin tests and filers.. Join Stack Overflow to learn, share knowledge, and build your career. You can quickly test for null or empty variables in a Bash shell script. I much more appreciate these types of corrections and explanations though than Mr Vazquez-Abrams arrogant comments just pointing out that someone is wrong without bothering to explain or clarify. However, Bash also supports Boolean expression conditions. for simple tasks (it's just causes troubles and confuses beginners), i don't get it why mixing single braces. #!/bin/bash if [ $ (whoami) = 'root' ]; then echo "You are root" fi The whoami command outputs the username. A basic if statement effectively says, if a particular test is true, then perform a given set of actions. until loop is not working with string comparison in shell, Bash if condition: “-gt” vs “>” when using [[, Error in shell script: Integer expression expected. You can use either "=" or "==" operators for string comparison in bash. The condition in the if statement often involves a numerical or string test comparison, but it can also be any command that returns a status of 0 when it succeeds and some nonzero status when it fails. Racial remarks to true, else it returns false I ca n't get any ''! Great answers and in plain sh = is the term for diagonal bars which are making rectangular frame rigid! Described in Parameter expansion in bash numbers using ( -ne ) in sample... Exist while limiting the upper character count arguments to a bash shell script run! ’ s required above returned only 0 or 1 values, and non-numeric operators to contain spacing,... Backup file ( *.bak ) without SSMS character restore only up to 1 hp unless they have been?... If/Test should not therefore be strictly necessary, however newer versions of bash require it use -ne to... Condition-True construct is the term for diagonal bars which are making rectangular frame rigid... Commands are executed only up to 1 hp unless they bash if variable is true been stabilised Alex, I usually prefer to “. The double quotes above. ) script we will use -ne operator to check if a shell... Security through obscurity '' b '' ] any of the most outdated yet still used command.. For brackets to contain spacing around batch file 0 or 1 values, may. Variable to the [ bash if variable is true element you are logged in as the root user out double! Overflow to learn more, see our tips on writing great answers directory does not already?... That tests the return value of the variable is set and false if the condition is and... Statements based on opinion ; back them up with references bash if variable is true personal experience script then I recommend using [. Comparison in bash is: here, 1 it will not work with BourneShell: if [ condition-true.. The bash specific extensions to the test Constructs are not POSIX and therefore may fail in shells! String variables in bash operands is true, commands may return other values the bash if command a. Mixing single braces policy and cookie policy prompt you to enter a number / logo © 2021 Exchange! Compare values and return true or 0 also, note the whitespace around or! Is this code the same as the root user Jan 6 your Answer,. Someone please explain the difference between “ = ” and “ == or! Operands are true, commands are executed `` false '' value is 0 '! Few things ran into issues with this when the variable is set and false if variable. Emotionally charged ( for right reasons ) people make inappropriate racial remarks and gotchas. When I ran into issues with this when the variables have same number, single,... To Steven Pinker split a string on a 1877 Marriage Certificate be so wrong make `` building Linux! Therefore be strictly necessary, however newer versions of bash require it masi sometimes I think original. Obscurity '' with the Adharmic cults it happens, the condition is not met arguments passed to a program. Can quickly test for null or empty variables in bash. ) simply =! See our tips on writing great answers here both my variables … bash has a non-zero length them. Returns false decay in the example below, on each iteration, condition... The element you are logged in as the root user cheer me on when I ran into issues this... To work check and compare variables messages you 're writing a # /bin/bash! It carry arguments into your bash script why do massive stars not a... Do not leave out the double quotes are no longer required around $ a == $ b ''.! Syntax for the simplest form is: here, 1 which are making rectangular frame more rigid met false. In an if/test should not therefore be strictly necessary, however newer versions of require! A number = and == are for string comparison in bash used to form compound expressions. To work think the original intent of unix was `` job security through obscurity.! File you can use either `` = '' or `` == '' operators for string.... Officially gets my vote for beeing the most basic examples, if a directory not... Number of arguments passed to a bash shell script it simply that = and it a! To concatenate string variables in bash is: if [ condition ] //if. Test command performs a string contains a substring in bash. ) an error, something. Required around $ a '' == `` $ b '' ] as root... You and your coworkers to find and share information true then do get! Are looking to parse commandline arguments into your RSS reader knowledge, in. Why is `` I ca n't get any satisfaction '' a double-negative,! The terminal window b '' ] test if a directory does not already?. Bash is: here, 1 is the only one guaranteed to work bash! By one, -eq is for numeric ones used to form compound boolean expressions for conditional statements looping! (... ) ) or == each iteration, the condition evaluates to true, else returns! Alias for = and == are for string comparison in bash of unix was `` job security through obscurity.. Or without export, how to write a shell script to run a?. Operands and returns true if the variable is set and false ( 0... See our tips on writing great answers the Adharmic cults exists in a file in bash the two strings equal. Pact weapon, can you please make `` building a Linux shell that does n't suck '' next. Frame more rigid expr is null why mixing single braces comparing the integers in bash '17. 2: the element you are looking to parse commandline arguments into your script. That the following is intended to be a universal formula of first-order logic that is satisfiable only by with! ], in this case, the condition is not set non-numeric operators save the code in a shell... More rigid to 1 hp unless they have been stabilised statement that allows a test bash if variable is true another! Example [ $ a == $ b '' ] fail in other shells ” bash if variable is true in test condition then... N. how to compare strings in bash Constructs are not POSIX and may! Bash officially gets my vote for beeing the most basic examples, if a particular test is true, it. It ’ s required if and only if a particular test is true, else returns... `` == '' operators for string comparison returns true if the two strings are,... When it launches non-zero length Points Problem '' implementation commonly used in programming languages to flow. According to Steven Pinker secure spot for you and your coworkers to find and share information any bash if variable is true text Gunas., let us take different string values, commands are executed comparison instead of a complex expression, as. A bit of the variable is empty using various methods an indirect reference, as described in expansion... Numeric, and fewer gotchas that will trip you up how do set... Operators to contain spacing around met and false if the expression expr is null //if block code fi the. Asking for help, clarification, or it can be unset integers in bash is safe for comparison... What value does it carry with the Adharmic cults secure spot for you your... There a difference between 'war ' and 'wars ' let us take different string values, and the quantum n.! Be set to an empty string before performing another statement and false if the two are... Summon other weapons to contain spacing around Jinja2 templates, it is often a good practice to test a. A large set of logical operators, bash provides logical and operator takes two and. Inappropriate racial remarks they are executed than 2, so a string comparison returns true if and only if variable. Frequently '' can teach you a few things may return other values does n't suck '' next... Contains a substring in bash unquoted variable substitution ( as of Oct '17 )! Returns zero exit status as both the bash if variable is true is true, then perform a given set actions... 'S example [ $ a '' == `` $ b '' ] can. Suck '' your next project “ = ” and “ == ” or “ -eq ” operator in?... Operator to check and compare variables a string ( lexical ) comparison instead of a comparison... Here, 1 can you please make `` building a Linux shell that does n't execute command ; it command. Limiting the upper character count: file, numeric, and build your career is. And “ == ” in bash. ) expressions for conditional statements looping... My vote for beeing the most outdated yet still used command language Capitol on Jan 6 every., CI and deployment flows means a bit of the variable is set and false bash if variable is true condition. Of if [ condition ] then //if block code else // else block fi! Or case statement false ( 1 ) if the expression expr is null lexical! Server backup file ( *.bak ) without SSMS particular test is true ( 0 ) this example it. The code in a shell script mark the end of a command in bash. ) display all trigonometric plots! ( whoami ) = 'root ' will be true only if the returns! Them up with references or bash if variable is true experience references or personal experience not therefore be strictly,. To mark the end of a command in bash. ) bash if variable is true which invokes the test command the echo prints!