Script for XCode 5 to generate fat static library for iOS containing i386, x86_64, armv7, armv7s and arm64 architectures.

build-fat-static-lib.sh

#!/bin/bash

# 
# This script was inspired by http://blog.diogot.com/blog/2013/09/18/static-libs-with-support-to-ios-5-and-arm64/
#
# This script uses a temporary folder for intermediate build products.
#
# Minimum deployment target is 5.0 for 32 bit architectures and for 64 bit architectures it is 7.0.
#

if [ -z "$1" ]; then
  echo
  echo "usage: $0 <project.xcodeproj> [<target>]"
  echo
  echo "for example: $0 ~/Documents/MyStaticLibProject.xcodeproj"
  echo
  echo "will generate a fat library (i386, x86_64, armv7, armv7s and arm64) named libMyStaticLibProject.a in the current folder for the target MyStaticLibProject."
  echo
  exit
fi

if [ ! -d "$1" ]; then
  echo
  echo "Error: $1 does not exist"
  echo
  exit
fi

MY_PROJECT="$1"
MY_PROJECT_NAME=$(basename "$1")

if [ -z "$2" ]; then
	MY_TARGET=${MY_PROJECT_NAME%.*}
else
	MY_TARGET="$2"
fi

MY_STATIC_LIB="lib${MY_TARGET}.a"
MY_BUILD_PATH=`mktemp -d -t "build"`

# armv7, armv7s
MY_ARM_BUILD_PATH="${MY_BUILD_PATH}/build-arm"
MY_CURRENT_BUILD_PATH="${MY_ARM_BUILD_PATH}"
xcodebuild -project "${MY_PROJECT}" -target "${MY_TARGET}" -configuration 'Release' -sdk 'iphoneos7.0' clean build ARCHS='armv7 armv7s' VALID_ARCHS='armv7 armv7s' IPHONEOS_DEPLOYMENT_TARGET='5.0' TARGET_BUILD_DIR="${MY_CURRENT_BUILD_PATH}" BUILT_PRODUCTS_DIR="${MY_CURRENT_BUILD_PATH}" OBJROOT="${MY_CURRENT_BUILD_PATH}" SYMROOT="${MY_CURRENT_BUILD_PATH}"

# arm64
MY_ARM64_BUILD_PATH="${MY_BUILD_PATH}/build-arm64"
MY_CURRENT_BUILD_PATH="${MY_ARM64_BUILD_PATH}"
xcodebuild -project "${MY_PROJECT}" -target "${MY_TARGET}" -configuration 'Release' -sdk 'iphoneos7.0' clean build ARCHS='arm64' VALID_ARCHS='arm64' IPHONEOS_DEPLOYMENT_TARGET='7.0' TARGET_BUILD_DIR="${MY_CURRENT_BUILD_PATH}" BUILT_PRODUCTS_DIR="${MY_CURRENT_BUILD_PATH}" OBJROOT="${MY_CURRENT_BUILD_PATH}" SYMROOT="${MY_CURRENT_BUILD_PATH}"

# i386
MY_I386_BUILD_PATH="${MY_BUILD_PATH}/build-i386"
MY_CURRENT_BUILD_PATH="${MY_I386_BUILD_PATH}"
xcodebuild -project "${MY_PROJECT}" -target "${MY_TARGET}" -configuration 'Release' -sdk 'iphonesimulator7.0' clean build ARCHS='i386' VALID_ARCHS='i386' IPHONEOS_DEPLOYMENT_TARGET='5.0' TARGET_BUILD_DIR="${MY_CURRENT_BUILD_PATH}" BUILT_PRODUCTS_DIR="${MY_CURRENT_BUILD_PATH}" OBJROOT="${MY_CURRENT_BUILD_PATH}" SYMROOT="${MY_CURRENT_BUILD_PATH}"

# x86_64
MY_X86_64_BUILD_PATH="${MY_BUILD_PATH}/build-x86_64"
MY_CURRENT_BUILD_PATH="${MY_X86_64_BUILD_PATH}"
xcodebuild -project "${MY_PROJECT}" -target "${MY_TARGET}" -configuration 'Release' -sdk 'iphonesimulator7.0' clean build ARCHS='x86_64' VALID_ARCHS='x86_64' IPHONEOS_DEPLOYMENT_TARGET='7.0' TARGET_BUILD_DIR="${MY_CURRENT_BUILD_PATH}" BUILT_PRODUCTS_DIR="${MY_CURRENT_BUILD_PATH}" OBJROOT="${MY_CURRENT_BUILD_PATH}" SYMROOT="${MY_CURRENT_BUILD_PATH}"

lipo -create "${MY_ARM_BUILD_PATH}/${MY_STATIC_LIB}" "${MY_ARM64_BUILD_PATH}/${MY_STATIC_LIB}" "${MY_I386_BUILD_PATH}/${MY_STATIC_LIB}" "${MY_X86_64_BUILD_PATH}/${MY_STATIC_LIB}" -output "${MY_STATIC_LIB}"

rm -rf "${MY_BUILD_PATH}"

For anyone having trouble with this in Xcode 6+, you should modify the -sdk versions to match the SDK's you have installed. For example with Xcode 6.4 you'd likely want to change the SDK's to 8.4 instead of 7.0. Also if you have any swift you'll need a deployment target of at least 7.0.