load from config file

cmd/shs_repl.go

@@ -18,21 +18,26 @@
 package main
 
 import (
-    "os"
     "fmt"
     "strconv"
     "github.com/chzyer/readline"
     "gitlab.com/whom/shs/ast"
     "gitlab.com/whom/shs/log"
-    "gitlab.com/whom/shs/stdlib"
+    "gitlab.com/whom/shs/config"
 )
 
 const (
     def_prompt  string = "λ "
 )
 
-func setLogLvl() {
-    loglvl := os.Getenv("SH_LOGGING")
+func setLogLvl(vars ast.VarTable) {
+    var loglvl string
+
+    loglvl_t := ast.GetVar("SH_LOGGING", vars)
+    if loglvl_t != nil {
+        loglvl = loglvl_t.Value()
+    }
+
     if loglvl != "" {
         llvl, err := strconv.ParseInt(loglvl, 10, 8)
         if err != nil {
@@ -46,23 +51,28 @@ func setLogLvl() {
 }
 
 func main() {
-    debug  := os.Getenv("SH_DEBUG_MODE")
-    hist   := os.Getenv("SH_HIST_FILE")
-    prompt := os.Getenv("SHS_SH_PROMPT")
+    var prompt string
+    var debug string
+    var hist string
 
-    var vars ast.VarTable
-    var funcs ast.FuncTable
-
-    funcs = stdlib.GenFuncTable()
-    vars = &map[string]*ast.Token{}
-
-    ast.InitVarTable(vars)
     ast.SyncTablesWithOSEnviron = true
     ast.ExecWhenFuncUndef = true
 
-    var err error
+    vars, funcs := config.InitFromConfig(".shsrc")
+    debug_t := ast.GetVar("SH_DEBUG_MODE", vars)
+    if debug_t != nil {
+        debug = debug_t.Value()
+    }
 
-    if prompt == "" {
+    hist_t := ast.GetVar("SH_HIST_FILE", vars)
+    if hist_t != nil {
+        hist = hist_t.Value()
+    }
+
+    prompt_t := ast.GetVar("SHS_SH_PROMPT", vars)
+    if prompt_t != nil {
+        prompt = prompt_t.Value()
+    } else {
         prompt = def_prompt
     }
 
@@ -79,7 +89,7 @@ func main() {
     }
 
     for {
-        setLogLvl()
+        setLogLvl(vars)
         text, err := rl.Readline()
         if err != nil {
             log.Log(log.ERR, "couldnt read user input: " + err.Error(), "repl")

config/config.go

@@ -0,0 +1,66 @@
+/*   SHS: Syntactically Homogeneous Shell
+ *   Copyright (C) 2019  Aidan Hahn
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package config
+
+import (
+    "os"
+    "io"
+    "bufio"
+    "gitlab.com/whom/shs/log"
+    "gitlab.com/whom/shs/ast"
+    "gitlab.com/whom/shs/stdlib"
+)
+
+func InitFromConfig(configFile string) (ast.VarTable, ast.FuncTable) {
+    funcs := stdlib.GenFuncTable()
+    vars := &map[string]*ast.Token{}
+
+    ast.InitVarTable(vars)
+
+    p := ast.GetVar("HOME", vars)
+    configFile = p.Value() + "/" + configFile
+
+    cfile, err := os.Open(configFile)
+    if err != nil {
+        log.Log(log.DEBUG,
+            "unable to open config file: " + err.Error(),
+            "config")
+        return vars, funcs
+    }
+
+    r := bufio.NewReader(cfile)
+    text, err := r.ReadString('\n')
+    for err != io.EOF {
+        if err != nil {
+            log.Log(log.ERR,
+                "unable to read from config file: " + err.Error(),
+                "config")
+            break
+        }
+
+        // Eval lines in config
+        ast.Lex(text).Eval(funcs, vars, false)
+        text, err = r.ReadString('\n')
+    }
+
+    log.Log(log.DEBUG,
+        "config file fully evaluated",
+        "config")
+    cfile.Close()
+    return vars, funcs
+}