fix: smarter AWK detection that supports nawk

.travis.yml

@@ -25,7 +25,7 @@ before_script:
   - tree -h
   - export
   - pushd bin; sha256sum -c install.sha256; popd
-  - fish $TRAVIS_BUILD_DIR/bin/install --offline --noninteractive --yes
+  - fish $TRAVIS_BUILD_DIR/bin/install --verbose --offline --noninteractive --yes
 
 script:
   - tests/run.fish

README.md

@@ -34,7 +34,7 @@ fish install --path=~/.local/share/omf --config=~/.config/omf
 You can verify the integrity of the downloaded installer by verifying the script against [this checksum](bin/install.sha256):
 
 ```
-bedbff763e374d5ca3367fa75b322302411e961947133eb22c7115083ba3a3ff  install
+4dd63d6a974a61c100cbe145ae46eac69edce985f20b061f353cc399b36c7587  install
 ```
 
 You can also install Oh My Fish with Git or with an offline source tarball downloaded from the [releases page][releases]:

bin/install

@@ -466,8 +466,9 @@ function sane_environment_check
     and test "$result[3]" = 1.2.3
     or abort (which sort)" is not a sane 'sort' implementation"
 
-  debug "Checking AWK version"
-  if not cmd awk -Wv | cmd grep -i -q AWK
+  debug "Checking for a working AWK interpreter"
+  cmd awk 'BEGIN{exit 42;}' < /dev/null ^ /dev/null
+  if not test $status -eq 42
     abort (which awk)" does not look like an AWK interpreter."
   end
 
@@ -581,8 +582,12 @@ end
 
 # A link-following `which` wrapper.
 function which
+  if type -q realpath
+    realpath (command which $argv)
+  else
     command readlink (command which $argv)
   end
+end
 
 
 # Execute an external command.

bin/install.sha256

@@ -1 +1 @@
-bedbff763e374d5ca3367fa75b322302411e961947133eb22c7115083ba3a3ff  install
+4dd63d6a974a61c100cbe145ae46eac69edce985f20b061f353cc399b36c7587  install