Release calc version 2.10.3t5.45

help/strerror

@@ -2,29 +2,46 @@ NAME
     strerror - returns a string describing an error value
 
 SYNOPSIS
-    strerror(x)
+    strerror([x])
 
 TYPES
-    x		error-value or non-negative integer
+    x		error-value or integer in [0, 32767], defaults to errno()
 
-    return	string or error-value
+    return	string
 
 DESCRIPTION
-    If x is an error-value, strerror(x) returns a string describing that value.
+    If x is the error-value with index n, strerror(x) and strerror(n)
+    return one of:
 
-    If x is an integer within the ranges for system, builtin, and user
-    defined error codes, the string describing error(x) is returned.
-    For integers outside these ranges, an "index out of range for
-    strerror" error is returned.
+		a system-generated message,
+		a calc-generated description,
+		a user-defined description created by newerror(str),
+		the string "Error n",
+
+    where, in the last form, n is represented decimally.
 
 EXAMPLE
-    > strerror(7)
-	"Bad argument for unary -"
+    System error messages may be different for different systems.
+    > errmax(errcount()+3)
+	    0
+    > strerror(2)
+ 	"No such file or directory"
 
     > x = 3 * ("a" + "b")
     > print strerror(x)
     Bad arguments for +
 
+    > a = newerror("alpha")
+    > print strerror(a)
+    alpha
+
+    > print strerror(999)
+    Error 999
+
+    > a = 1/0
+    > print strerror()
+    Division by zero
+
 LIMITS
     none
 
@@ -32,4 +49,4 @@ LIBRARY
     none
 
 SEE ALSO
-    error, iserror, errno
+    errcount, errmax, error, iserror, errno, newerror, errorcodes