1 #!/bin/bash 2 # 3 # A simple script to wrap the execution of a command so that it stores its 4 # output and return value into a file and then process it to later on. 5 # 6 # This is meant to be used in a makefile, specifically to allow for the output 7 # of a command to be stored in a file and added to the dist list, even if the 8 # command actually failed. 9 # 10 # For example, your makefile might include: 11 # 12 # my_target := lint 13 # my_target_output := $(OUT_DIR)/lint-output.txt 14 # my_target_retval := $(OUT_DIR)/lint-retval.txt 15 # 16 # $(my_target_output) $(my_target_retval): PRIVATE_MODULE := $(my_target) 17 # $(my_target_output) $(my_target_retval): PRIVATE_OUTPUT := $(my_target_output) 18 # $(my_target_output) $(my_target_retval): PRIVATE_RETVAL := $(my_target_retval) 19 # $(my_target_output) $(my_target_retval): 20 # $(PATH)/wrapper.sh \ 21 # $(PRIVATE_MODULE) \ 22 # $(PRIVATE_OUTPUT) \ 23 # $(PRIVATE_RETVAL) \ 24 # wrap \ 25 # $(PATH)/run-list.sh $(LOCAL_PATH)/src 26 # 27 # $(my_target): PRIVATE_MODULE := $(my_target) 28 # $(my_target): PRIVATE_OUTPUT := $(my_target_output) 29 # $(my_target): PRIVATE_RETVAL := $(my_target_retval) 30 # $(my_target): $(my_target_output) $(my_target_retval) 31 # $(PATH)/wrapper.sh \ 32 # $(PRIVATE_MODULE) \ 33 # $(PRIVATE_OUTPUT) \ 34 # $(PRIVATE_RETVAL) \ 35 # eval 36 37 set -euo pipefail 38 39 # Terminate with a fatal error. 40 function fatal() { 41 echo "Fatal: $*" 42 exit 113 43 } 44 45 function main() { 46 local module="${1-}"; shift || fatal "missing argument: module" 47 local output="${1-}"; shift || fatal "missing argument: output" 48 local retval="${1-}"; shift || fatal "missing argument: retval" 49 local action="${1-}"; shift || fatal "missing argument: action" 50 # The rest of the arguments are the command to run. 51 52 if [ "$action" = 'wrap' ]; then 53 # Run the command specified by the rest of arguments ("$@") and save output 54 # and return value. 55 echo 0 >"${retval}" 56 "$@" >"${output}" 2>&1 || echo "$?" >"${retval}" 57 58 # Wrapping itself is always successful. 59 return 60 elif [ "$action" = 'eval' ]; then 61 local result="$(cat "${retval}")" 62 if [ "$result" = 0 ]; then 63 # If successful only print the last few lines. 64 tail -n 5 "$output" | sed -e "s/^/${module}: /" 65 else 66 # Print the entire output on failure. 67 cat "$output" | sed -e "s/^/${module}: /" 68 fi 69 # Evaluating returns the stored return value. 70 return "$result" 71 else 72 fatal "invalid action: $action" 73 fi 74 } 75 76 main "$@" 77
