The Elk Shell Language

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Comparisons with Bash ​

Writing to files ​

elk
# bash
echo hello world > file.txt
echo appended line >> file.txt
some-program &> errors.txt
echo This won't be visible > /dev/null

# elk
"hello world" | write file.txt
"appended line" | append file.txt
some-program |err write errors.txt
echo This won't be visible | dispose # disposeErr for errors
# bash
echo hello world > file.txt
echo appended line >> file.txt
some-program &> errors.txt
echo This won't be visible > /dev/null

# elk
"hello world" | write file.txt
"appended line" | append file.txt
some-program |err write errors.txt
echo This won't be visible | dispose # disposeErr for errors

Conditionals ​

elk
# bash
if [[ -n "$var" ]]; then
   echo is not empty
else
   echo is empty
fi

# elk
if not var {
   echo is not empty
} else {
   echo is empty
}

# or
if var != nil: "is not empty" else "is empty" | println
# bash
if [[ -n "$var" ]]; then
   echo is not empty
else
   echo is empty
fi

# elk
if not var {
   echo is not empty
} else {
   echo is empty
}

# or
if var != nil: "is not empty" else "is empty" | println

Reading a file line by line ​

elk
# bash
cat lines.txt | while read line 
do
   echo Line: $line
done

# elk
# option 1
cat lines.txt | each => line: echo("Line: ${line}")

# otion 2
for line in cat("lines.txt"):
   println("Line:", line)
# bash
cat lines.txt | while read line 
do
   echo Line: $line
done

# elk
# option 1
cat lines.txt | each => line: echo("Line: ${line}")

# otion 2
for line in cat("lines.txt"):
   println("Line:", line)

Substrings ​

elk
# bash
string="hello"
substring=${string:0:3}

# elk
let string = "hello"
let substring = string[..3]
# bash
string="hello"
substring=${string:0:3}

# elk
let string = "hello"
let substring = string[..3]

Grepping the last lines of a file ​

elk
# bash
tail -n 5 file.txt | grep hello

# elk
tail -n 5 file.txt | grep hello

# it's the same!
# bash
tail -n 5 file.txt | grep hello

# elk
tail -n 5 file.txt | grep hello

# it's the same!