Modifications to get an actual Go module

Signed-off-by: Geoffroy Vallee <[email protected]>

.github/workflows/go.yml

@@ -0,0 +1,33 @@
+name: Go
+on: [push, pull_request]
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Set up Go 1.12
+      uses: actions/setup-go@v1
+      with:
+        go-version: 1.12
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v1
+
+    - name: Get dependencies
+      run: |
+        go get -v -t -d ./...
+        if [ -f Gopkg.toml ]; then
+            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+            dep ensure
+        fi
+
+    - name: Build and test
+      run: |
+        go build ./...
+        go test
+      env:
+        GOPATH: /tmp/go
+

go.mod

@@ -0,0 +1,3 @@
+module github.com/gvallee/syserror
+
+go 1.12

pkg/syserror/syserror.go

@@ -0,0 +1,40 @@
+// Copyright (c) 2019, Geoffroy Vallee, All rights reserved
+// Copyright (c) 2019, Sylabs Inc. All rights reserved.
+// This software is licensed under a 3-clause BSD license. Please consult the
+// LICENSE.md file distributed with the sources of this project regarding your
+// rights to use or distribute this software.
+
+package syserror
+
+import (
+	"fmt"
+)
+
+type SysError struct {
+	msg  string // message associated to the error
+	code int    // error code
+}
+
+// Predefined errors
+var NoErr = SysError{"Success", 0}                   // Success
+var ErrFatal = SysError{"Fatal error", -1}           // Generic fatal error
+var ErrOutOfRes = SysError{"Out of resources", -2}   // Out of resources (e.g., out of memory)
+var ErrNotAvailable = SysError{"Not available", -3}  // The target is not available (e.g., a file does not exist)
+var ErrDataOverflow = SysError{"Data overflow", -4}  // Data overflow
+var ErrInvalidArg = SysError{"Invalid argument", -5} // Invalid function argument
+
+func (err *SysError) Error() string {
+	if err.code != 0 {
+		return fmt.Sprintf("ERROR: %d: %s", err.code, err.msg)
+	} else {
+		return fmt.Sprintf("%d: %s", err.code, err.msg)
+	}
+}
+
+func (_error SysError) getMsg() string {
+	return _error.msg
+}
+
+func (_error SysError) getCode() int {
+	return _error.code
+}