add mksvg function

modules/tex.nix

@@ -23,24 +23,23 @@
 
       if [[ -z "$tex_file" ]]; then
         # Build all .tex files in current directory
-        local tex_files=(*.tex)
-        if [[ ''${#tex_files[@]} -eq 0 ]] || [[ ! -f "''${tex_files[0]}" ]]; then
-          echo "No .tex files found in current directory"
-          return 1
-        fi
-
-        for file in "''${tex_files[@]}"; do
+        local found=0
+        for file in *.tex(N); do
+          found=1
           echo "Building $file..."
           latexmk -pdf -bibtex -shell-escape -interaction=nonstopmode \
             -output-directory="$output_dir" -f "$file"
 
-          # Copy PDF to current directory
           local basename="''${file%.tex}"
           if [[ -f "$output_dir/$basename.pdf" ]]; then
             cp "$output_dir/$basename.pdf" "./"
             echo "Copied $basename.pdf to current directory"
           fi
         done
+        if [[ $found -eq 0 ]]; then
+          echo "No .tex files found in current directory"
+          return 1
+        fi
       else
         if [[ ! -f "$tex_file" ]]; then
           echo "File not found: $tex_file"
@@ -59,6 +58,61 @@
       fi
     }
 
+    # Generate standalone PDF from LaTeX equation
+    # Usage: mksvg <equation> <filename>
+    # Example: mksvg 'E = mc^2' energy
+    function mksvg() {
+      local equation="''${1}"
+      local filename="''${2}"
+
+      if [[ -z "$equation" ]] || [[ -z "$filename" ]]; then
+        echo "Usage: mksvg <equation> <filename>"
+        echo "Example: mksvg 'E = mc^2' energy"
+        return 1
+      fi
+
+      printf '%s\n' "$equation" > "''${filename}.texeq"
+
+      local temp_tex="''${filename}_temp.tex"
+      {
+        printf '%s\n' '\documentclass{standalone}'
+        printf '%s\n' '\usepackage{amsmath}'
+        printf '%s\n' '\usepackage{amssymb}'
+        printf '%s\n' '\begin{document}'
+        printf '%s%s%s\n' '$' "$equation" '$'
+        printf '%s\n' '\end{document}'
+      } > "$temp_tex"
+
+      pdflatex -interaction=nonstopmode "$temp_tex" > /dev/null 2>&1
+
+      if [[ -f "''${filename}_temp.pdf" ]]; then
+        mv "''${filename}_temp.pdf" "''${filename}.pdf"
+        echo "Generated ''${filename}.pdf"
+      else
+        echo "Failed to generate PDF"
+        rm -f "$temp_tex"
+        return 1
+      fi
+
+      rm -f "$temp_tex" "''${filename}_temp.aux" "''${filename}_temp.log"
+    }
+
+    # Regenerate PDFs from all .texeq files in current directory
+    function mksvg-all() {
+      local found=0
+      for file in *.texeq(N); do
+        found=1
+        local filename="''${file%.texeq}"
+        local equation="$(cat "$file")"
+        echo "Regenerating ''${filename}.pdf..."
+        mksvg "$equation" "$filename"
+      done
+      if [[ $found -eq 0 ]]; then
+        echo "No .texeq files found in current directory"
+        return 1
+      fi
+    }
+
     # Continuous compilation mode - watch and auto-rebuild
     # Usage: mkpdf-watch <file.tex>
     function mkpdf-watch() {