Question: What does echo do in Unix?

Echo is a Unix/Linux command tool used for displaying lines of text or string which are passed as arguments on the command line. This is one of the basic command in linux and most commonly used in shell scripts.

What is echo $? In Linux?

echo $? will return the exit status of last command. You got 127 that is the exit status of last executed command exited with some error (most probably). Commands on successful completion exit with an exit status of 0 (most probably).

What is the difference between echo and printf in Unix?

echo always exits with a 0 status, and simply prints arguments followed by an end of line character on the standard output, while printf allows for definition of a formatting string and gives a non-zero exit status code upon failure. printf has more control over the output format.

What does $? Do in Bash?

$? expands to the exit status of the most recently executed foreground pipeline. See the Special Parameters section of the Bash manual. In simpler terms, it’s the exit status of the last command.

What does echo $0 Do?

Originally Posted by David the H. $0 is the name of the running process. If you use it inside a shell, then it will return the name of the shell. If you use it inside a script, it will be the name of the script.

What is $home in Linux?

The Linux home directory is a directory for a particular user of the system and consists of individual files. It is also referred to as the login directory. This is the first place that occurs after logging into a Linux system. It is automatically created as “/home” for each user in the directory’.

What is the difference between print and printf?

The difference between printf and print is the format argument. This is an expression whose value is taken as a string; it specifies how to output each of the other arguments. It is called the format string.

Should I use echo or printf?

If all one wishes to do is emit one or more lines of text terminated by newlines, then echo suffices. If anything more clever is intended, specifically including a “partial line” that does not have the newline, then printf is best for that purpose.

Is echo same as print?

“echo and print are more or less the same. They are both used to output data to the screen. The differences are small: echo has no return value while print has a return value of 1 so it can be used in expressions. echo can take multiple parameters (although such usage is rare) while print can take one argument.

What is bash symbol?

Special bash characters and their meaning

What is Echo $1?

$1 is the argument passed for shell script. Suppose, you run ./myscript.sh hello 123. then. $1 will be hello. $2 will be 123.