Shell variable interaction (#276)

* Shell variable interaction

* remove amber_test println

* return type Bool

now shelle_var_set and shell_unset return true or false

* Update src/std/main.ab

Co-authored-by: Phoenix Himself <pkaras.it@gmail.com>

* Update src/std/main.ab

Co-authored-by: Phoenix Himself <pkaras.it@gmail.com>

* Update src/std/main.ab

Co-authored-by: Phoenix Himself <pkaras.it@gmail.com>

* Update src/std/main.ab

Co-authored-by: Phoenix Himself <pkaras.it@gmail.com>

* Update src/std/main.ab

Co-authored-by: Phoenix Himself <pkaras.it@gmail.com>

* add shell_constant_get test

* define set/get/unset shell_var function as faillabe

---------

Co-authored-by: Phoenix Himself <pkaras.it@gmail.com>

src/std/main.ab

@@ -239,3 +239,30 @@ pub fun get_env_var(var: Text): Text {
 pub fun load_env_file(): Null {
     unsafe $export "\$(xargs < .env)" > /dev/null$
 }
+
+pub fun shell_isset(name: Text): Bool {
+    $[[ ! -z \$\{!{nameof name}+z} ]]$ failed {
+        return false
+    }
+    return true
+}
+
+pub fun shell_constant_set(name: Text, val: Text): Null {
+    $readonly \${nameof name}="\${nameof val}" 2> /dev/null$?
+}
+
+pub fun shell_constant_get(name: Text): Text {
+    return $echo \$\{!{nameof name}}$?
+}
+
+pub fun shell_var_set(name: Text, val: Text): Null {
+    $declare -g \${nameof name}="\${nameof val}" 2> /dev/null$?
+}
+
+pub fun shell_var_get(name: Text): Text {
+    return $echo \$\{!{nameof name}}$?
+}
+
+pub fun shell_unset(name: Text): Null {
+    $unset {name}$?
+}

src/tests/stdlib/shell_constant_get.ab

@@ -0,0 +1,5 @@
+import * from "std"
+main {
+    unsafe shell_constant_set("test_shell_constant_get", "Hello Amber!")
+    unsafe $echo "\$test_shell_constant_get"$
+} 

src/tests/stdlib/shell_constant_get.output.txt

@@ -0,0 +1 @@
+Hello Amber!

src/tests/stdlib/shell_constant_set.ab

@@ -0,0 +1,10 @@
+import * from "std"
+main {
+    unsafe shell_constant_set("test_shell_constant_set", "Hello Amber")
+    let str = ""
+    str += unsafe $echo "\$test_shell_constant_set"$
+    shell_constant_set("test_shell_constant_set", "Hello Amber") failed {
+        str += " Shell Constant!"
+    }
+    echo str
+} 

src/tests/stdlib/shell_constant_set.output.txt

@@ -0,0 +1 @@
+Hello Amber Shell Constant!

src/tests/stdlib/shell_isset.ab

@@ -0,0 +1,11 @@
+import * from "std"
+main {
+    unsafe $test_var_isset="test"$
+    if shell_isset("test_var_isset") {
+        echo "test_var_isset"
+    }
+
+    if shell_isset("test_var_isset2") {
+        echo "test_var_isset2"
+    }
+} 

src/tests/stdlib/shell_isset.output.txt

@@ -0,0 +1 @@
+test_var_isset

src/tests/stdlib/shell_unset.ab

@@ -0,0 +1,7 @@
+import * from "std"
+main {
+    unsafe shell_var_set("test_shell_unset", "Hello Amber!")
+    unsafe $echo \$test_shell_unset$
+    unsafe shell_unset("test_shell_unset")
+    unsafe $echo \$test_shell_unset$
+}

src/tests/stdlib/shell_unset.output.txt

@@ -0,0 +1 @@
+Hello Amber!

src/tests/stdlib/shell_var_get.ab

@@ -0,0 +1,5 @@
+import * from "std"
+main {
+    unsafe $declare -g test_shell_var_get="Hello Amber!"$
+    echo unsafe shell_var_get("test_shell_var_get")
+}

src/tests/stdlib/shell_var_get.output.txt

@@ -0,0 +1 @@
+Hello Amber!

src/tests/stdlib/shell_var_set.ab

@@ -0,0 +1,5 @@
+import * from "std"
+main {
+    unsafe shell_var_set("test_shell_var_set", "Hello Amber!")
+    unsafe $echo \$test_shell_var_set$
+}

src/tests/stdlib/shell_var_set.output.txt

@@ -0,0 +1 @@
+Hello Amber!