share: Introduce the sh directory, mktemp implementation

This commit installs an `sh` directory in the `share` directory, in which
implementations of popular tools that might not be available on a user's
system sit.

In order for a shell scope to use those implementations if the regular
binaries are unavailable, the `PATH` variable has to be modified as follows,
at the beginning of the scope:

```
%sh{
    export PATH="${PATH}:${kak_runtime}/sh"

    <code>
}
```

rc/base/lint.kak

@@ -8,6 +8,9 @@ decl -hidden range-specs lint_errors
 
 def lint -docstring 'Parse the current buffer with a linter' %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-lint.XXXXXXXX)
         mkfifo "$dir"/fifo
         printf '%s\n' "eval -no-hooks write $dir/buf"

rc/base/spell.kak

@@ -11,6 +11,9 @@ Formats of language supported:
     spell %{
     try %{ add-highlighter ranges 'spell_regions' }
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         file=$(mktemp -d -t kak-spell.XXXXXXXX)/buffer
         printf 'eval -no-hooks write %s\n' "${file}"
         printf 'set buffer spell_tmp_file %s\n' "${file}"

rc/core/doc.kak

@@ -3,6 +3,9 @@ decl -docstring "name of the client in which documentation is to be displayed" \
 
 def -hidden -params 1..2 doc-open %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         manout=$(mktemp /tmp/kak-man-XXXXXX)
 
         # Those options are handled by the `man-db` implementation

rc/core/grep.kak

@@ -8,6 +8,9 @@ def -params .. -file-completion \
     -docstring %{grep [<arguments>]: grep utility wrapper
 All the optional arguments are forwarded to the grep utility} \
     grep %{ %sh{
+    # fallback implementation: mktemp
+    export PATH="${PATH}:${kak_runtime}/sh"
+
      output=$(mktemp -d -t kak-grep.XXXXXXXX)/fifo
      mkfifo ${output}
      if [ $# -gt 0 ]; then

rc/core/make.kak

@@ -11,6 +11,9 @@ def -params .. \
     -docstring %{make [<arguments>]: make utility wrapper
 All the optional arguments are forwarded to the make utility} \
     make %{ %sh{
+    # fallback implementation: mktemp
+    export PATH="${PATH}:${kak_runtime}/sh"
+
      output=$(mktemp -d -t kak-make.XXXXXXXX)/fifo
      mkfifo ${output}
      ( eval ${kak_opt_makecmd} "$@" > ${output} 2>&1 ) > /dev/null 2>&1 < /dev/null &

rc/core/man.kak

@@ -28,6 +28,9 @@ hook global WinSetOption filetype=(?!man).* %{
 }
 
 def -hidden -params 1..2 man-impl %{ %sh{
+    # fallback implementation: mktemp
+    export PATH="${PATH}:${kak_runtime}/sh"
+
     manout=$(mktemp /tmp/kak-man-XXXXXX)
     colout=$(mktemp /tmp/kak-man-XXXXXX)
     MANWIDTH=${kak_window_width} man "$@" > $manout

rc/extra/clang.kak

@@ -11,6 +11,9 @@ def -params ..1 \
 The syntaxic errors detected during parsing are shown when auto-diagnostics are enabled} \
     clang-parse %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-clang.XXXXXXXX)
         mkfifo ${dir}/fifo
         printf %s\\n "set buffer clang_tmp_dir ${dir}"

rc/extra/git-tools.kak

@@ -33,6 +33,9 @@ Available commands:\n-add\n-rm\n-blame\n-commit\n-checkout\n-diff\n-hide-blame\n
   } \
   git %{ %sh{
     show_git_cmd_output() {
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         local filetype
         case "$1" in
            show|diff) filetype=diff ;;

rc/extra/go-tools.kak

@@ -13,6 +13,9 @@ decl -hidden completions gocode_completions
 
 def go-complete -docstring "Complete the current selection with gocode" %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-go.XXXXXXXX)
         printf %s\\n "set buffer go_complete_tmp_dir ${dir}"
         printf %s\\n "eval -no-hooks write ${dir}/buf"
@@ -56,6 +59,9 @@ decl -hidden str go_format_tmp_dir
 def -params ..1 go-format \
     -docstring "go-format [-use-goimports]: custom formatter for go files" %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-go.XXXXXXXX)
         printf %s\\n "set buffer go_format_tmp_dir ${dir}"
         printf %s\\n "eval -no-hooks write ${dir}/buf"
@@ -87,6 +93,9 @@ decl -hidden str go_doc_tmp_dir
 # FIXME text escaping
 def -hidden -params 1..2 gogetdoc-cmd %{
    %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-go.XXXXXXXX)
         printf %s\\n "set buffer go_doc_tmp_dir ${dir}"
         printf %s\\n "eval -no-hooks write ${dir}/buf"

rc/extra/jedi.kak

@@ -5,6 +5,9 @@ decl -docstring "colon separated list of path added to `python`'s $PYTHONPATH en
 
 def jedi-complete -docstring "Complete the current selection" %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-jedi.XXXXXXXX)
         mkfifo ${dir}/fifo
         printf %s\\n "set buffer jedi_tmp_dir ${dir}"

rc/extra/racer.kak

@@ -3,6 +3,9 @@ decl -hidden completions racer_completions
 
 def racer-complete -docstring "Complete the current selection with racer" %{
     %sh{
+        # fallback implementation: mktemp
+        export PATH="${PATH}:${kak_runtime}/sh"
+
         dir=$(mktemp -d -t kak-racer.XXXXXXXX)
         printf %s\\n "set buffer racer_tmp_dir ${dir}"
         printf %s\\n "eval -no-hooks %{ write ${dir}/buf }"

share/kak/sh/mktemp

@@ -0,0 +1,68 @@
+#!/bin/sh
+## mktemp fallback implementation
+## Options supported:
+##  -u, --dry-run: only print the path to a temporary file without generating it
+##  -d, --directory: create a directory
+##  -p, --tmpdir: use $TMPDIR as base path if possible, /tmp otherwise
+##                this flag does NOT take any argument
+
+error() {
+    printf 'mktemp: %s\n' "$*" >&2
+    exit 1
+}
+
+main() {
+    flag_dry_run=0
+    flag_directory=0
+    flag_tmpdir=0
+
+    for arg in "$@"; do
+        case "${arg}" in
+            -u|--dry-run) flag_dry_run=1;;
+            -d|--directory) flag_directory=1;;
+            -p|--tmpdir) flag_tmpdir=1;;
+            -*) error "Unsupported flag ${arg}";;
+            *) break;;
+        esac
+
+        shift
+    done
+
+    if [ $# -eq 0 ]; then
+        template="tmp.XXXXXXXXXX"
+        flag_tmpdir=1
+    else
+        template="${1}"
+        if ! printf %s\\n "${template}" | grep -q 'XXX$'; then
+            error "The template must end with at least 3 consecutive 'X's"
+        fi
+    fi
+
+    if [ ${flag_tmpdir} -ne 0 ]; then
+        dir="${TMPDIR:-/tmp}/"
+    fi
+
+    template=$(printf %s\\n "${template}" | awk '{
+        idx = match($0, /X+$/) - 1
+        printf "%." idx "s", $0
+        system("cat /dev/urandom | tr -dc a-zA-Z0-9 | fold -w " RLENGTH " | head -n 1")
+    }')
+
+    path="${dir}${template}"
+    if [ ${flag_dry_run} -eq 0 ]; then
+        if [ ${flag_directory} -ne 0 ]; then
+            mkdir -p "${path}"
+            chmod u+rwx "${path}"
+        else
+            if [ -n "${dir}" ]; then
+                mkdir -p "${dir}"
+            fi
+            touch "${path}"
+            chmod u+rw "${path}"
+        fi
+    fi
+
+    printf %s\\n "${path}"
+}
+
+main "$@"

src/Makefile

@@ -108,6 +108,7 @@ distclean: clean
 
 installdirs:
 	install -d $(bindir) \
+		$(sharedir)/sh \
 		$(sharedir)/rc/base \
 		$(sharedir)/rc/core \
 		$(sharedir)/rc/extra \
@@ -117,6 +118,7 @@ installdirs:
 
 install: kak man doc installdirs
 	install -m 0755 kak $(bindir)
+	install -m 0755 ../share/kak/sh/* $(sharedir)/sh
 	install -m 0644 ../share/kak/kakrc $(sharedir)
 	install -m 0644 ../rc/base/* $(sharedir)/rc/base
 	install -m 0644 ../rc/core/* $(sharedir)/rc/core