initial commit with basic logging

5 files changed, 200 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..750baeb
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+result
+result-*
diff --git a/bash-lib.sh b/bash-lib.sh
new file mode 100644
index 0000000..83819df
--- /dev/null
+++ b/bash-lib.sh
@@ -0,0 +1,98 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+IFS=$'\n\t'
+
+shopt -s nullglob
+
+tput() {
+        # If tput fails, it just means less colors
+        command tput "$@" 2> /dev/null || true
+}
+
+NORMAL="$(tput sgr0)"
+readonly NORMAL
+BOLD="$(tput bold)"
+readonly BOLD
+
+RED="$(tput setaf 1)"
+readonly RED
+GREEN="$(tput setaf 2)"
+readonly GREEN
+YELLOW="$(tput setaf 3)"
+readonly YELLOW
+BLUE="$(tput setaf 4)"
+readonly BLUE
+PURPLE="$(tput setaf 5)"
+readonly PURPLE
+CYAN="$(tput setaf 6)"
+readonly CYAN
+WHITE="$(tput setaf 7)"
+readonly WHITE
+
+readonly BASH_LIB_DEBUG_VAR="${BASH_LIB_NAME:-BASH}_DEBUG"
+
+is_debug() {
+        [ "${!BASH_LIB_DEBUG_VAR:-0}" -ge 1 ]
+}
+
+is_trace() {
+        [ "${!BASH_LIB_DEBUG_VAR:-0}" -ge 2 ]
+}
+
+declare -a VERBOSE_ARG
+if is_debug; then
+        VERBOSE_ARG=("--verbose")
+else
+        VERBOSE_ARG=()
+fi
+readonly VERBOSE_ARG
+
+echoe() {
+        IFS=" " echo "$@" >&2
+}
+
+log() {
+        local level="$1"
+        local color="$2"
+        local message="$3"
+        shift 3
+        local rest="$@"
+
+        echoe "${BOLD}${color}${level} ${WHITE}${message}${NORMAL}" "${rest[@]}"
+}
+
+trace() {
+        if is_trace; then
+                log "Trace:  " "${PURPLE}" "$@"
+        fi
+}
+
+debug() {
+        if is_debug; then
+                log "Debug:  " "${GREEN}" "$@"
+        fi
+}
+
+info() {
+        log "Info:   " "${CYAN}" "$@"
+}
+
+warn() {
+        log "Warning:" "${YELLOW}" "$@"
+}
+
+error() {
+        log "Error:  " "${RED}" "$@"
+}
+
+critical() {
+        error "$@"
+        # Useful for triggering the error trap system
+        false
+}
+
+fatal() {
+        error "$@"
+        exit 1
+}
diff --git a/demo.sh b/demo.sh
new file mode 100644
index 0000000..256d091
--- /dev/null
+++ b/demo.sh
@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+
+readonly BASH_LIB_NAME=DEMO
+source ./bash-lib.sh
+
+# Set `DEMO_DEBUG=1` to enable debug messages
+
+trace "this is a trace message" "with additional data"
+debug "this is a debugging message" "with additional data"
+info "this is an informational message" "with additional data"
+warn "this is a warning message" "with additional data"
+error "this is an error message" "with additional data"
+
+# Like echo, but to stderr
+echoe '------------------------------'
+
+if is_debug; then
+        info "Debugging messages:" on
+else
+        info "Debugging messages:" off
+fi
+
+if is_trace; then
+        info "Trace messages:" on
+else
+        info "Trace messages:" off
+fi
+
+echoe '------------------------------'
+
+# Use critical with `set +e` if you want to trap errors
+(
+        function handle_error() {
+                info "handling error..."
+        }
+
+        set +e
+        trap "handle_error" ERR
+
+        critical "this is a critical error:" "this will allow some error recovery"
+        info "but with 'set +e', the program continues its course"
+)
+
+echoe '------------------------------'
+
+info "use 'fatal()' in either case if you want to quit with an error message"
+fatal "some unrecoverable error occurred, exiting"
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..e03bfad
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1634851050,
+        "narHash": "sha256-N83GlSGPJJdcqhUxSCS/WwW5pksYf3VP1M13cDRTSVA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c91f3de5adaf1de973b797ef7485e441a65b8935",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..ad3d540
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,27 @@
+{
+  description = "A simple bash library for your scripting needs";
+
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, flake-utils }:
+    with flake-utils.lib;
+    eachSystem allSystems (system: {
+
+      # Convert a path to a derivation
+      # This is done so we don't depend on nixpkgs
+      packages.bash-lib = with builtins; derivation {
+        name = "bash-lib.sh";
+        src = readFile ./bash-lib.sh;
+        inherit system;
+
+        builder = "/bin/sh";
+        args = [
+          (toFile "builder.sh" ''
+            echo "$src" > $out
+          '')
+        ];
+      };
+
+      defaultPackage = self.packages.${system}.bash-lib;
+    });
+}