add compatibility flags for a bunch of scripts (part 1)

sh/argc

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush -ksh +mksh -oksh +osh +posh +yash +zsh
 
 argc() { ### @- validate the number of arguments in a function.
     ### ```sh

sh/arith

@@ -1,5 +1,5 @@
 #!/usr/bin/env zsh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush +ksh +mksh +oksh +osh +posh +yash +zsh
 
 # though technically compatible with other shells,
 # extra functionality is through zsh's extended arithmetic functions.

sh/askey

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush +ksh +mksh +oksh +osh +posh +yash +zsh
 
 askey() {
     printf '\033[100m 00 \033[m \033[100m 01 \033[m \033[100m 02 \033[m \033[100m 03 \033[m \033[100m 04 \033[m \033[100m 05 \033[m \033[100m 06 \033[m \033[100m 07 \033[m \033[100m 08 \033[m \033[100m 09 \033[m \033[100m 0A \033[m \033[100m 0B \033[m \033[100m 0C \033[m \033[100m 0D \033[m \033[100m 0E \033[m \033[100m 0F \033[m

sh/autosync

@@ -1,7 +1,8 @@
 #!/usr/bin/env zsh
-# compat: -ash -bash -dash +zsh
+# compat: -ash -bash -dash -hush -ksh -mksh -oksh -osh -posh -yash +zsh
 
 # TODO: portable way of dodging aliases to allow other shell support?
+# TODO: rewrite to use entr instead of inotifywait.
 
 autosync() { ### @-
     ### combine `inotifywait` and `rsync`.

sh/bak

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush -ksh +mksh +oksh +osh +posh +yash +zsh
 
 bak() { ### @-
     ### backup files by creating copies and appending ".bak" to their names.

sh/baknow

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: -ash +bash +dash -hush -ksh +mksh -oksh +osh +posh +yash +zsh
 
 baknow() { ### @- backup files by appending their timestamps given by [`now`.](#now)
     ### ```

sh/baks

@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 # backup, timestamped
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash -hush -ksh +mksh +oksh +osh +posh +yash +zsh
 
 baks() { ### @-
     ### backup files by copying each and appending *the current* date-time,

sh/bin

@@ -1,5 +1,5 @@
 #!/usr/bin/env zsh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush -ksh +mksh +oksh +osh +posh +yash +zsh
 
 # though technically compatible with other shells,
 # extra functionality is through zsh's extended arithmetic functions.

sh/burl

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash -hush +ksh +mksh +oksh +osh +posh +yash +zsh
 
 burl() ( ### @-
     ### turn bash into a makeshift HTTP client.
@@ -31,6 +31,8 @@ burl() ( ### @-
     ### }
     ### ```
 
+    # shells with /dev/tcp and /dev/udp support: bash, ksh, yash.
+
     ! (set -o pipefail) 2>&- || set -o pipefail
     (: </dev/udp/localhost/0) 2>&- && net=y || net=
     [ $'' ] && r=$(printf \\r) || r=$'\r'

sh/busiest

@@ -1,5 +1,5 @@
 #!/usr/bin/env zsh
-# compat: -ash -bash -dash +zsh
+# compat: -ash -bash -dash -hush -ksh -mksh -oksh -osh -posh -yash +zsh
 
 busiest() { ### @-
     ### list directories in descending order by the number of files in them,

sh/colors

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# compat: -ash +bash -dash +zsh
+# compat: -ash +bash -dash -hush +ksh -mksh -oksh +osh -posh -yash +zsh
 
 colors() { ### @-
     ### display all combinations of foreground and background terminal colors.

sh/colors2

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush +ksh +mksh +oksh +osh +posh +yash +zsh
 
 colors2() {
     [ $# -eq 0 ] || { printf "%s\n" "$0: does not take arguments" >&2; return 1; }

sh/confirm

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush +ksh +mksh +oksh +osh +posh +yash +zsh
 
 ### @ confirm
 ### display a simple yes-or-no prompt and return 0-or-1 respectively.

sh/dated

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: +ash +bash +dash +hush -ksh +mksh +oksh +osh +posh +yash +zsh
 
 dated() {
     local ts= u=0

sh/days

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
+# compat: -ash +bash +dash +hush +ksh +mksh +oksh +osh +posh +yash +zsh
 
 days() { ### @-
     ### compute the number of days since a given date.
@@ -8,6 +8,7 @@ days() { ### @-
     ### $ days 'January 1 1970'
     ### 18838
     ### ```
+    # FIXME: this doesn't always work in busybox because its `date` is too simple.
     [ $# -le 1 ] || { printf "%s\n" "$0: too many arguments" >&2; return 1; }
     echo $(( ($(date +%s) - $(date -d "$1" +%s)) / 60 / 60 / 24 ))
 }

sh/decently

@@ -1,7 +1,5 @@
 #!/usr/bin/env sh
-# compat: +ash +bash +dash +zsh
-
-# TODO: check if this is compatible with busybox.
+# compat: +ash +bash +dash +hush -ksh +mksh +oksh +osh +posh +yash +zsh
 
 decently() ( ### @-
     ### given a list of directories, update the last-modified timestamp