all: modify all.bash to use scripts/lib.sh

Terminal colors for log levels and the runcmd helper function is
added to scripts/lib.sh. all.bash now these functions.

Updates b/151162757

Change-Id: Ic0ce1c89214bfa8704571647ead784d2b7ee37fb
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/687549
CI-Result: Cloud Build <devtools-proctor-result-processor@system.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

all.bash

@@ -3,7 +3,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-source devtools/lib.sh || { echo "Are you at repo root?"; exit 1; }
+source scripts/lib.sh || { echo "Are you at repo root?"; exit 1; }
 
 warnout() {
   while read line; do

scripts/lib.sh

@@ -0,0 +1,43 @@
+# Copyright 2019 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+# Library of useful bash functions and variables.
+
+if [ -t 1 ] && which tput >/dev/null 2>&1; then
+  RED="$(tput setaf 1)"
+  GREEN="$(tput setaf 2)"
+  YELLOW="$(tput setaf 3)"
+  NORMAL="$(tput sgr0)"
+else
+  RED=""
+  GREEN=""
+  YELLOW=""
+  NORMAL=""
+fi
+
+EXIT_CODE=0
+
+info() { echo -e "${GREEN}$@${NORMAL}" 1>&2; }
+warn() { echo -e "${YELLOW}$@${NORMAL}" 1>&2; }
+err() { echo -e "${RED}$@${NORMAL}" 1>&2; EXIT_CODE=1; }
+
+die() {
+  err $@
+  exit 1
+}
+
+# runcmd prints an info log describing the command that is about to be run, and
+# then runs it. It sets EXIT_CODE to non-zero if the command fails, but does not exit
+# the script.
+runcmd() {
+  msg="$@"
+  # Truncate command logging for narrow terminals.
+  # Account for the 2 characters of '$ '.
+  maxwidth=$(( $(tput cols) - 2 ))
+  if [[ ${#msg} -gt $maxwidth ]]; then
+    msg="${msg::$(( maxwidth - 3 ))}..."
+  fi
+  info "\$ $msg"
+  $@ || err "command failed"
+}