init

bash/next/next.sh

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+# Get the file name in any numbered series of text files and open with emacs
+
+# Usage:
+#     $ . next [descriptor]
+
+# Handles an optional string descriptor. Like this:
+#    $ ls
+#    011.blah.md
+#    $ . next foo
+#    012.foo.md
+
+# File format:
+# in regex terms:
+#   [0-9]+\.[.*\.]*md|txt
+# in plain terms:
+#   [leadings numbers with consistent width].[optional string descriptor and . separator][md|txt]
+
+# what this does:
+# ls | grep [regex for number.*.md] | get last | awk script to increment the digits, preserve the zero prefix, add string descriptor if supplied, and add back extension
+
+# Note the egrep '^\d.*\.md|txt' (matches whole string) to account for an optional string between the initial number and the file extension. As in '435.blah.md'.
+
+# old version, relied on python, which didn't handle leading zeros properly, but treated them as binary:
+# ls | grep '\d.*\.md' | tail -n 1 | sed s/'\..*md'// | sed s/.*/'print & + 1'/ | python - | sed s/.*/'&.md/'
+
+# BUGS
+
+# 1. Emacs won't accept piped input as a file name. I'd rather keep this as a separate utility, which only printed the right filename, and then use an alias to pipe the filename to emacs, or invoke it manually.
+
+# A.
+# What I want, is this syntax:
+# next [optional arg]
+# To both get the file and open emacs with it.
+
+# B.
+# But this doesn't work:
+# next | emacs
+# Because it sees the stdin the pipe wants to feed it as a substitute for the tty in the new session, rather than as input for startup only, i.e. the filename.
+
+# C.
+# Wrapping the whole shell command here works, like this:
+# emacs `ls | grep ...`
+
+# But emacs doesn't like being run inside a child level shell, because it can't load .emacs properly. So you must run this file within the current shell using ".", like this:
+# . next
+# . next foo
+
+# D.
+# This does not work, because .profile must be executed, meaning that the "" expression is peeked by the shell:
+# alias next="emacs `next.sh $1`"
+
+# E.
+# This does not work either, because the arg never gets filled out when evoked:
+# alias next='emacs `next.sh $1`'
+
+# F.
+# This works and is the current solution:
+# alias next='. next.sh'
+
+# Which relies on 2 somewhat obscured facts:
+# 1. This script calls emacs itself, wrapping the real work in ``
+# 2. The alias is a simple substitution, which fortunately seems to happen before args are processed by the shell, meaning that the shell sees: ". next.sh arg"
+# 3. NOTE: the symbolic link in the PATH should not be simply "next", because it
+# may in certain situations conflict with the alias. The link should be "next.sh" -> ~/config/..
+# 4. NOTE: I use 'e' rather than 'emacs', to use my clever emacs/emacsclient function.
+
+e `
+
+ls | egrep '^[[:digit:]].*\.md|txt' | tail -n 1 | awk '
+
+BEGIN {
+# set field separator, blank by default
+FS = "."
+}
+
+{
+newnum = $1 + 1
+nzeros = length($1) - length(int(newnum))
+
+# could I do this with a simpler regex to select all leading zeros?
+leadingzeros = ""
+if (nzeros > 0)
+  for (i = 1; i <= nzeros; i++)
+    leadingzeros = sprintf("%s%s", leadingzeros, "0")
+
+if (nzeros > 0)
+  newnum = sprintf("%s%s", leadingzeros, newnum)
+
+# start by prefixing the number, now with leading zeros
+finalstr = newnum
+
+# allow an arg input to fill out descriptor string.
+# single quote break to allow the shell to fill it out, double quotes so awk will treat it as a string
+arg = "'$1'"
+
+if (arg != "")
+    finalstr = sprintf("%s.%s", finalstr, arg)
+
+# append last field by default
+finalstr = sprintf("%s.%s", finalstr, $NF)
+
+# previous loop to reassemble all fields. But I do not want the old middle string here
+# Keeping it here for reference.
+# for (i = 2; i <= NF; i++)
+#   finalstr = sprintf("%s.%s", finalstr, $i)
+# }
+
+}
+
+END {
+print finalstr
+}'
+`