From ca9fd3a8fe05ebf490024fd06014e7086bf86ab4 Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Fri, 11 Dec 2015 14:11:28 +1300
Subject: Add keep

---
 bash/bashrc.d/keep.bash | 134 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 bash/bashrc.d/keep.bash

(limited to 'bash')

diff --git a/bash/bashrc.d/keep.bash b/bash/bashrc.d/keep.bash
new file mode 100644
index 00000000..bdb5c2de
--- /dev/null
+++ b/bash/bashrc.d/keep.bash
@@ -0,0 +1,134 @@
+#
+# Main function for bashkeep; provided with a list of NAMEs, whether shell
+# functions or variables, writes the current definition of each NAME to a
+# directory $BASHKEEP (defaults to ~/.bashkeep.d) with a .bash suffix, each
+# of which is reloaded each time this file is called. This allows you to
+# quickly arrange to keep that useful shell function or variable you made
+# inline on subsequent logins.
+#
+keep() {
+
+    # Figure out the directory to which we're reading and writing these scripts
+    local bashkeep
+    bashkeep=${BASHKEEP:-$HOME/.bashkeep.d}
+
+    # Parse options
+    local opt delete
+    local OPTERR OPTIND OPTARG
+    while getopts 'dh' opt ; do
+        case $opt in
+
+            # -d given; means delete the keepfiles for the given names
+            d)
+                delete=1
+                ;;
+
+            # -h given; means show help
+            h)
+                cat <<EOF
+$FUNCNAME: Keep variables and functions in shell permanently by writing them to
+named scripts iterated on shell start, in \$BASHKEEP (defaults to
+~/.bashkeep.d).
+
+USAGE:
+  $FUNCNAME
+    List all the current kept variables and functions
+  $FUNCNAME NAME1 [NAME2 ...]
+    Write the current definition for the given NAMEs to keep files
+  $FUNCNAME -d NAME1 [NAME2 ...]
+    Delete the keep files for the given NAMEs
+  $FUNCNAME -h
+    Show this help
+
+EOF
+                return
+                ;;
+
+            # Unknown other option
+            \?)
+                printf 'bash: %s -%s: invalid option\n' \
+                    "$FUNCNAME" "$opt" >&2
+                return 2
+                ;;
+        esac
+    done
+    shift "$((OPTIND-1))"
+
+    # If any arguments left, we must be either keeping or deleting
+    if (($#)) ; then
+
+        # Start keeping count of any errors
+        local -i errors
+        errors=0
+
+        # Iterate through the NAMEs given
+        local name
+        for name in "$@" ; do
+
+            # Check NAMEs for validity
+            case $name in
+
+                # NAME must start with letters or an underscore, and contain no
+                # characters besides letters, numbers, or underscores
+                *[^a-zA-Z0-9_]*|[^a-zA-Z_]*)
+                    printf 'bash: %s: %s not a valid NAME\n' \
+                        "$FUNCNAME" "$name" >&2
+                    ((errors++))
+                    ;;
+
+                # NAME is valid, proceed
+                *)
+
+                    # If -d was given, delete the keep files for the NAME
+                    if ((delete)) ; then
+                        rm -- "$bashkeep"/"$name".bash \
+                            || ((errors++))
+
+                    # Otherwise, attempt to create the keep file, using an
+                    # appropriate call to the declare builtin
+                    else
+                        { case $(type -t "$name") in
+                            'function')
+                                declare -f -- "$name"
+                                ;;
+                            *)
+                                declare -p -- "$name"
+                                ;;
+                        esac ; } > "$bashkeep"/"$name".bash \
+                            || ((errors++))
+                    fi
+                    ;;
+            esac
+        done
+
+        # Return 1 if we accrued any errors, 0 otherwise
+        return "$((errors > 0))"
+    fi
+
+    # Deleting is an error, since we need at least one argument
+    if ((delete)) ; then
+        printf 'bash: %s: must specify at least one NAME to delete\n'
+            "$FUNCNAME" >&2
+        return 2
+    fi
+
+    # Otherwise the user must want us to print all the NAMEs kept
+    local -a keeps
+    keeps=("${bashkeep}"/*.bash)
+    keeps=("${keeps[@]##*/}")
+    keeps=("${keeps[@]%.bash}")
+    printf '%s\n' "${keeps[@]}"
+}
+
+# Complete calls to keep with existing function names and variable names
+complete -A function -A variable keep
+
+# Load any existing scripts in bashkeep
+if [[ -d ${BASHKEEP:-$HOME/.bashkeep.d} ]] ; then
+    for bashkeep in "${BASHKEEP:-$HOME/.bashkeep.d}"/*.bash ; do
+        [[ -e $bashkeep ]] || continue
+        source "$bashkeep"
+    done
+    unset -v bashkeep
+fi
+
-- 
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