1 files changed, 104 insertions, 0 deletions
diff --git a/ves.fish b/ves.fish
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index 0000000..3315f61
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+++ b/ves.fish
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+# ves.fish
+#
+# fish shell shim for sh-ves. Runs each ves command in a POSIX sh subshell
+# against the real implementation, then diffs the subshell's resulting
+# environment against fish's and replays the changes with set -gx / set -e.
+# The activation save-state is carried in exported SHVES_SAVED_* variables,
+# so it survives between subshell invocations.
+#
+# Install this file to ~/.config/fish/functions/ves.fish (make install does
+# this automatically when fish is present).
+
+function ves --description 'sh-ves: Bourne Shell Virtual Environment System'
+    if not set -q SHVES_SCRIPTS_DIR
+        set -gx SHVES_SCRIPTS_DIR $HOME/.local/bin/ves_scripts
+    end
+
+    if not test -f "$SHVES_SCRIPTS_DIR/ves-init.sh"
+        printf "ERROR: sh-ves scripts not found in [%s]. Is sh-ves installed?\n" "$SHVES_SCRIPTS_DIR" >&2
+        return 1
+    end
+
+    set -l dump (mktemp)
+
+    # Resolve env(1) to an absolute path up front: the command may rewrite
+    # PATH inside the subshell, which would otherwise make the dump fail.
+    set -l envbin (command -v env)
+    if test -z "$envbin"
+        set envbin /usr/bin/env
+    end
+
+    # Run the real command, then dump the subshell's final environment
+    # NUL-delimited (values may contain newlines) for replay into fish.
+    VES_ENV_DUMP=$dump VES_ENV_BIN=$envbin sh -c '
+        . "$SHVES_SCRIPTS_DIR"/ves-init.sh
+        ves "$@"
+        _shves_status=$?
+        "$VES_ENV_BIN" -0 > "$VES_ENV_DUMP"
+        exit $_shves_status
+    ' ves $argv
+    set -l ret $status
+
+    # An empty dump means the subshell could not write its environment at
+    # all; replaying it would wrongly erase every exported variable.
+    if not test -s $dump
+        printf "ERROR: failed to capture subshell environment, shell state unchanged.\n" >&2
+        rm -f $dump
+        return 1
+    end
+
+    # Variables managed by the wrapper machinery itself, plus per-process
+    # bookkeeping that should never be replayed into the parent shell.
+    set -l skip VES_ENV_DUMP VES_ENV_BIN PWD OLDPWD SHLVL _
+
+    # fish list-style path variables: replay these split on ':' so fish
+    # keeps treating them as lists.
+    set -l pathvars PATH CDPATH MANPATH
+
+    set -l seen
+    for entry in (string split0 < $dump)
+        set -l kv (string split -m1 = -- $entry)
+        set -l name $kv[1]
+        set -l value $kv[2]
+
+        # entries that are not well-formed variable names (e.g. exported
+        # multiline values' continuation, or odd env entries) are skipped
+        if not string match -qr '^[a-zA-Z_][a-zA-Z0-9_]*$' -- $name
+            continue
+        end
+        if contains -- $name $skip
+            continue
+        end
+
+        set -a seen $name
+
+        if contains -- $name $pathvars
+            set -l new (string split : -- $value)
+            if not set -q $name
+                set -gx $name $new
+            else if test "$new" != "$$name"
+                set -gx $name $new
+            end
+        else
+            if not set -q $name
+                set -gx $name $value
+            else if test "$value" != "$$name"
+                set -gx $name $value
+            end
+        end
+    end
+
+    # Anything fish exports that vanished from the subshell environment
+    # was unset by the command (e.g. by ves deactivate).
+    for name in (set -nx)
+        if contains -- $name $skip
+            continue
+        end
+        if not contains -- $name $seen
+            set -e $name
+        end
+    end
+
+    rm -f $dump
+    return $ret
+end