Add Linear Search in Awk

archive/a/awk/linear-search.awk

@@ -0,0 +1,49 @@
+function usage() {
+    print "Usage: please provide a list of integers (\"1, 4, 5, 11, 12\") and the integer to find (\"11\")"
+    exit(1)
+}
+
+function str_to_number(s) {
+    return (s ~ /^\s*[+-]*[0-9]+\s*$/) ? s + 0 : "ERROR"
+}
+
+function str_to_array(s, arr) {
+    split(s, str_arr, ",")
+    for (idx in str_arr) {
+        result = str_to_number(str_arr[idx])
+        if (result == "ERROR") {
+            delete arr
+            arr[1] = "ERROR"
+            break
+        } else {
+            arr[idx] = result
+        }
+    }
+}
+
+function linear_search(arr, target) {
+    result = 0
+    for (idx in arr) {
+        if (arr[idx] == target) {
+            result = idx
+            break
+        }
+    }
+
+    return result
+}
+
+BEGIN {
+    if (ARGC < 3) {
+        usage()
+    }
+
+    str_to_array(ARGV[1], arr)
+    target = str_to_number(ARGV[2])
+    if (!length(arr) || arr[1] == "ERROR" || target == "ERROR") {
+        usage()
+    }
+
+    idx = linear_search(arr, target)
+    print (idx > 0) ? "true" : "false"
+}