last.sh will exit 1 when no file found; handle it in next.sh. meaning um next works in empty dirs

README.md

@@ -80,25 +80,24 @@ Note the optional setup of `embark`, which allows us to visit files just by invo
 
 The "command line interface" is just a small set of convenient scripts: since these are just text files, we could just as easily create everything manually.
 
-1. To get started, create an empty directory to serve as content origin. It doesn't matter where or what it's called, since the shell scripts only assume a sequentially numbered collection of files.
-
-2. Decide on a zero-width for your series and seed the first file:
-
-  ```sh
-  touch 01.md
-  ```
-
-  The rest of the commands will now work with this width.
+To get started, create an empty directory to serve as content origin. It doesn't matter where or what it's called, since the shell scripts only assume a sequentially numbered collection of files.
 
 ## next
 
-Create a new file, open it with emacsclient, and run `um-journal-header`:
+To create a new file:
 
 ```sh
 um next
 ```
 
-Yields:
+This will create the file, open it with emacsclient, and run `um-journal-header` in that file:
+
+```markdown
+# 01.md
+: 2024.01.14
+```
+
+If you save this file and run `um next` again you get:
 
 ```markdown
 # 02.md

shell/last.sh

@@ -1,3 +1,5 @@
+#!/bin/bash
+
 # Get the last file name of any numbered series of text files.
 
 # file format:
@@ -6,6 +8,14 @@
 # in plain terms:
 #   [leading numbers with consistent width].[optional string descriptor and . separator][md|txt]
 
-# TODO: signal no file found, so that next knows to create one.
-# Grep exits 1, but tail exits 0.
-ls | egrep '^[[:digit:]].*\.md|txt' | tail -n 1
+UMALLFILES=`ls | egrep '^[[:digit:]].*\.(md|txt)'`
+LASTSTATUS=$?
+
+# NOTE: if we don't stop and signal here, tail will exit 0
+if [ "$LASTSTATUS" -ne 0 ]; then
+    echo "no files found" >&2
+    exit 1
+fi
+
+# NOTE: if var isn't quoted echo will change newlines to spaces
+echo "$UMALLFILES" | tail -n 1

shell/next.sh

@@ -23,8 +23,11 @@
 #
 # See https://git.bth.moi/bth/um#next
 
-# NOTE the optional $1 arg passed to awk with -v:
-NEXTFILE=`$UMBASEPATH/last.sh | awk -f $UMBASEPATH/next.awk -v arg=$1`
+# NOTE: handle the exit 1 case of last.sh
+LASTFILE=`$UMBASEPATH/last.sh || echo $UMDEFAULTINIT`
+
+# NOTE: the optional $1 arg passed to awk with -v:
+NEXTFILE=`echo $LASTFILE | awk -f $UMBASEPATH/next.awk -v arg=$1`
 
 # tag is optional second arg to this script
 TAGINSERT='(previous-line) (insert "+ %s\\n") (next-line)'
@@ -40,10 +43,12 @@ fi
 UMELISP="(progn (find-file \"$NEXTFILE\") (um-journal-header) $UMTAG (message \"creating $NEXTFILE\"))"
 
 # for testing and piping
-if [ $UMNEXTECHO = true ]; then
+if [ $UMNEXTECHO ]; then
     echo $UMELISP
 else
     # HACK: emacs won't accept piped input as a file name, so we use --eval to open
     # the file via find-file.
     emacsclient --eval "$UMELISP"
 fi
+
+exit 0

shell/test/um.bats

@@ -10,6 +10,7 @@ setup() {
     # FIXME: why isn't this working?
     # PATH="$DIR/../:$PATH"
     # commands depend on being in the journal/ path.
+    export ORIGPWD=`pwd`
     cd $DIR/mockjournal
     # so that we can run next.sh without dealing with emacsclient.
     export UMNEXTECHO=true
@@ -17,7 +18,8 @@ setup() {
 
 teardown() {
     export UMNEXTECHO=false
-    cd -
+    cd $ORIGPWD
+    git restore $DIR/mockjournal
 }
 
 @test "um usage" {
@@ -67,6 +69,13 @@ um_next_awk() {
     assert_output '099.poo.md'
 }
 
+@test "um last empty" {
+    cd foo
+    run um last
+    assert_failure
+    assert_output 'no files found'
+}
+
 @test "um cat" {
     run um cat 001.md 002.blah.md
     assert_output '# 001

shell/um

@@ -2,6 +2,11 @@
 
 # export so that we can use it in subscripts.
 export UMBASEPATH=`realpath $0 | xargs dirname`
+# TODO: load a config file?
+export UMDEFAULTINIT='000.md'
+
+# TODO: decide if getopts would be better. positional args supposed to be bad.
+# https://stackoverflow.com/a/28466267
 
 # catch first arguments with $1
 case "$1" in
@@ -22,6 +27,6 @@ case "$1" in
         $UMBASEPATH/tag.sh $2
         ;;
     *)
-        echo "usage: um (next|last|cat|rename|tag)"
+        echo "usage: um (next|last|cat|rename|tag)"; exit 1
         ;;
 esac