Add basic support for ANSI color escape codes.

Nim's `terminal` library provides ANSI terminal escape support, but
only when writing directly to a File handle. This commit adds the
`term{FG,BG}` procedures and `termReset` constant to help with embedding
ANSI escape codes in string data.

.gitignore

@@ -0,0 +1,3 @@
+nimcache/
+cliutils
+*.sw?

cliutils.nim

@@ -1,5 +1,7 @@
-import docopt, json, posix, nre, strutils
+import docopt, json, osproc, posix, nre, streams, strtabs, terminal, unicode
 import os except sleep
+import strutils except toUpper, toLower
+
 
 type
   CombinedConfig* = object
@@ -13,10 +15,98 @@ proc getVal*(cfg: CombinedConfig, key, default: string): string =
 
   if cfg.docopt[argKey]: return $cfg.docopt[argKey]
   elif existsEnv(envKey): return getEnv(envKey)
-  elif cfg.json.hasKey(jsonKey): return cfg.json[jsonKey].getStr
+  elif cfg.json.hasKey(jsonKey):
+    let node = cfg.json[jsonKey]
+    case node.kind
+    of JString: return node.getStr
+    of JInt: return $node.getInt
+    of JFloat: return $node.getFloat
+    of JBool: return $node.getBool
+    of JNull: return ""
+    of JObject: return $node
+    of JArray: return $node
   else: return default
 
 
+proc loadEnv*(): StringTableRef =
+  result = newStringTable()
+
+  for k, v in envPairs():
+    result[k] = v
+
+## Process execution
+type HandleProcMsgCB* = proc (outMsg: TaintedString,
+                              errMsg: TaintedString, cmd: string): void
+
+proc sendMsg*(h: HandleProcMsgCB, outMsg: TaintedString,
+              errMsg: TaintedString = nil, cmd: string = ""): void =
+  if h != nil: h(outMsg, errMsg, cmd)
+
+proc makeProcMsgHandler*(outSink, errSink: File, prefixCmd: bool = true): HandleProcMsgCB =
+  result = proc(outMsg, errMsg: TaintedString, cmd: string): void {.closure.} =
+    let prefix = if cmd == nil or not prefixCmd: "" else: cmd & ": "
+    if outMsg != nil: outSink.writeLine(prefix & outMsg)
+    if errMsg != nil: errSink.writeLine(prefix & errMsg)
+
+proc makeProcMsgHandler*(outSink, errSink: Stream, prefixCmd: bool = true): HandleProcMsgCB =
+  result = proc(outMsg, errMsg: TaintedString, cmd: string): void {.closure.} =
+    let prefix = if cmd == nil or not prefixCmd: "" else: cmd & ": "
+    if outMsg != nil: outSink.writeLine(prefix & outMsg)
+    if errMsg != nil: errSink.writeLine(prefix & errMsg)
+
+proc combineProcMsgHandlers*(a, b: HandleProcMsgCB): HandleProcMsgCB =
+  if a == nil: result = b
+  elif b == nil: result = a
+  else:
+    result = proc(cmd: string, outMsg, errMsg: TaintedString): void =
+      a(cmd, outMsg, errMsg)
+      b(cmd, outMsg, errMsg)
+
+proc waitFor*(p: Process, msgCB: HandleProcMsgCB, procCmd: string = ""): int =
+
+  var pout = outputStream(p)
+  var perr = errorStream(p)
+
+  var line = newStringOfCap(120).TaintedString
+  while true:
+    if pout.readLine(line):
+      msgCB.sendMsg(line, nil, procCmd)
+    elif perr.readLine(line):
+      msgCB.sendMsg(nil, line, procCmd)
+    else:
+      result = peekExitCode(p)
+      if result != -1: break
+  close(p)
+
+proc exec*(command: string, workingDir: string = "",
+           args: openArray[string] = [], env: StringTableRef = nil,
+           options: set[ProcessOption] = {poUsePath},
+           msgCB: HandleProcMsgCB = nil): int
+    {.tags: [ExecIOEffect, ReadIOEffect, RootEffect], gcsafe.} =
+
+  var p = startProcess(command, workingDir, args, env, options)
+  result = waitFor(p, msgCB, command)
+
+proc execWithOutput*(command: string, workingDir:string = "",
+           args: openArray[string] = [], env: StringTableRef = nil,
+           options: set[ProcessOption] = {poUsePath},
+           msgCB: HandleProcMsgCB = nil):
+    tuple[output: TaintedString, error: TaintedString, exitCode: int] =
+
+  result = (TaintedString"", TaintedString"", -1)
+  var outSeq, errSeq: seq[TaintedString]
+  outSeq = @[]; errSeq = @[]
+  var outputCollector = combineProcMsgHandlers(msgCB,
+    proc(outMsg, errMsg: TaintedString, cmd: string): void {.closure.} =
+      if outMsg != nil: outSeq.add(outMsg)
+      if errMsg != nil: errSeq.add(errMsg))
+
+  result[2] = exec(command, workingDir, args, env, options, outputCollector)
+  result[0] = outSeq.join("\n")
+  result[1] = errSeq.join("\n")
+
+## Daemonize
+
 var
   pidFileInner: string
   fi, fo, fe: File
@@ -29,7 +119,7 @@ proc onStop(sig: cint) {.noconv.} =
 
   quit(QuitSuccess)
 
-proc daemonize*(pidfile, si, so, se: string, daemonMain: proc(): void): int =
+proc daemonize*(pidfile, si, so, se: string, daemonMain: proc(): void): Pid =
 
   if fileExists(pidfile):
     raise newException(IOError, "pidfile " & pidfile & " already exists, daemon already running?")
@@ -81,3 +171,15 @@ proc daemonize*(pidfile, si, so, se: string, daemonMain: proc(): void): int =
     daemonMain()
 
   return pid1
+
+proc termFG*(color: ForegroundColor, bright, bold = false): string =
+  var colorVal = ord(color)
+  if bright: inc(colorVal, 60)
+  return "\e[" & $colorVal & (if bold: ";1" else: "") & "m"
+
+proc termBG*(color: BackgroundColor, bright, bold = false): string =
+  var colorVal = ord(color)
+  if bright: inc(colorVal, 60)
+  return "\e[" & $colorVal & "m"
+
+const termReset* = "\e[0;m"

cliutils.nimble

@@ -1,11 +1,11 @@
 # Package
 
-version       = "0.1.0"
+version       = "0.4.0"
 author        = "Jonathan Bernard"
 description   = "Helper functions for writing command line interfaces."
 license       = "MIT"
 
 # Dependencies
 
-requires @["nim >= 0.15.3", "docopt"]
+requires @["nim >= 0.18.0", "docopt"]