sed_edit

Make small edits to files using sed patterns for single-line changes, pattern replacements, and simple text transformations.

Instructions

Make small edits to files using sed patterns. Efficient for single-line changes, pattern replacements, and simple text transformations.

Input Schema

TableJSON Schema

Name	Required	Description
`file`	Yes	Path to the file to edit
`pattern`	Yes	Sed pattern (e.g., "s/old/new/g" for substitution)
`backup`	No	Create backup file before editing
`preview`	No	Preview changes without modifying file

Implementation Reference

src/index.ts:567-606 (handler)

The handler for the 'sed_edit' tool. Parses arguments, checks file existence, constructs and executes a Perl command using the provided sed-like pattern for editing the file. Supports preview mode (with diff) and backup creation. Returns success message or preview output.

case 'sed_edit': {
  const { file, pattern, backup = true, preview = false } = args;
  
  // Check if file exists
  if (!existsSync(file)) {
    throw new Error(`File not found: ${file}`);
  }
  
  // Build sed command - use perl for better compatibility
  let sedCmd;
  if (preview) {
    // For preview, create a temp copy and diff
    const tempFile = `${file}.preview.tmp`;
    await execAsync(`rm -f .bak; cp '${file}' '${tempFile}'`);
    
    // Apply change to temp file
    sedCmd = `perl -i -pe '${pattern}' '${tempFile}' && diff -u '${file}' '${tempFile}' | head -50; rm -f '${tempFile}'`;
  } else {
    // Use perl for actual edits (more portable than sed)
    const backupExt = backup ? '.bak' : '';
    sedCmd = `perl -i${backupExt} -pe '${pattern}' '${file}'`;
  }
  
  const { stdout, stderr } = await execAsync(sedCmd);
  
  if (stderr) {
    throw new Error(`Sed error: ${stderr}`);
  }
  
  return {
    content: [
      {
        type: 'text',
        text: preview ? 
          `Preview of changes:\n${stdout || 'No changes would be made'}` :
          `Successfully edited ${file}${backup ? ' (backup created as .bak)' : ''}`
      }
    ]
  };
}

src/index.ts:39-66 (schema)

The input schema definition for the sed_edit tool, defining parameters: file (required string), pattern (required string), backup (optional boolean, default true), preview (optional boolean, default false).

{
  name: 'sed_edit',
  description: 'Make small edits to files using sed patterns. Efficient for single-line changes, pattern replacements, and simple text transformations.',
  inputSchema: {
    type: 'object',
    properties: {
      file: {
        type: 'string',
        description: 'Path to the file to edit'
      },
      pattern: {
        type: 'string',
        description: 'Sed pattern (e.g., "s/old/new/g" for substitution)'
      },
      backup: {
        type: 'boolean',
        default: true,
        description: 'Create backup file before editing'
      },
      preview: {
        type: 'boolean',
        default: false,
        description: 'Preview changes without modifying file'
      }
    },
    required: ['file', 'pattern']
  }
},

src/index.ts:36-280 (registration)

The registration of all tools including sed_edit via the ListToolsRequestSchema handler, which returns the list of available tools with their schemas.

server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: 'sed_edit',
        description: 'Make small edits to files using sed patterns. Efficient for single-line changes, pattern replacements, and simple text transformations.',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'Path to the file to edit'
            },
            pattern: {
              type: 'string',
              description: 'Sed pattern (e.g., "s/old/new/g" for substitution)'
            },
            backup: {
              type: 'boolean',
              default: true,
              description: 'Create backup file before editing'
            },
            preview: {
              type: 'boolean',
              default: false,
              description: 'Preview changes without modifying file'
            }
          },
          required: ['file', 'pattern']
        }
      },
      {
        name: 'sed_multifile',
        description: 'Apply sed pattern to multiple files matching a glob pattern',
        inputSchema: {
          type: 'object',
          properties: {
            pattern: {
              type: 'string',
              description: 'Sed pattern to apply'
            },
            filePattern: {
              type: 'string',
              description: 'File glob pattern (e.g., "*.ts", "src/**/*.js")'
            },
            directory: {
              type: 'string',
              default: '.',
              description: 'Starting directory for search'
            },
            backup: {
              type: 'boolean',
              default: true,
              description: 'Create backup files'
            }
          },
          required: ['pattern', 'filePattern']
        }
      },
      {
        name: 'awk_process',
        description: 'Process files using AWK for more complex operations like column manipulation, calculations, or conditional processing',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'Input file path'
            },
            script: {
              type: 'string',
              description: 'AWK script to execute'
            },
            outputFile: {
              type: 'string',
              description: 'Output file path (optional, defaults to stdout)'
            }
          },
          required: ['file', 'script']
        }
      },
      {
        name: 'quick_replace',
        description: 'Simple find and replace across a file without regex',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'File to edit'
            },
            find: {
              type: 'string',
              description: 'Text to find (literal, not regex)'
            },
            replace: {
              type: 'string',
              description: 'Text to replace with'
            },
            all: {
              type: 'boolean',
              default: true,
              description: 'Replace all occurrences (false = first only)'
            }
          },
          required: ['file', 'find', 'replace']
        }
      },
      {
        name: 'line_edit',
        description: 'Edit specific lines by number or range',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'File to edit'
            },
            lineNumber: {
              type: 'number',
              description: 'Line number to edit (1-based)'
            },
            lineRange: {
              type: 'string',
              description: 'Line range (e.g., "10,20" or "5,$")'
            },
            action: {
              type: 'string',
              enum: ['replace', 'delete', 'insert_after', 'insert_before'],
              description: 'Action to perform'
            },
            content: {
              type: 'string',
              description: 'New content (for replace/insert actions)'
            }
          },
          required: ['file', 'action']
        }
      },
      {
        name: 'perl_edit',
        description: 'Edit files using Perl one-liners (more powerful than sed, better cross-platform support)',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'File to edit'
            },
            script: {
              type: 'string', 
              description: 'Perl script (e.g., "s/old/new/g" or "$_ = uc" for uppercase)'
            },
            backup: {
              type: 'boolean',
              default: true,
              description: 'Create backup file'
            },
            multiline: {
              type: 'boolean',
              default: false,
              description: 'Enable multiline mode (-0777)'
            }
          },
          required: ['file', 'script']
        }
      },
      {
        name: 'diff_preview', 
        description: 'Preview what changes would be made by showing a diff',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'File to preview changes for'
            },
            command: {
              type: 'string',
              description: 'Command that would make changes (e.g., "s/old/new/g")'
            },
            tool: {
              type: 'string',
              enum: ['sed', 'perl', 'awk'],
              default: 'perl',
              description: 'Which tool to use for the preview'
            }
          },
          required: ['file', 'command']
        }
      },
      {
        name: 'restore_backup',
        description: 'Restore a file from its most recent backup (.bak)',
        inputSchema: {
          type: 'object',
          properties: {
            file: {
              type: 'string',
              description: 'File to restore from backup'
            },
            keepBackup: {
              type: 'boolean',
              default: true,
              description: 'Keep the backup file after restoring'
            }
          },
          required: ['file']
        }
      },
      {
        name: 'list_backups',
        description: 'List all backup files in a directory',
        inputSchema: {
          type: 'object',
          properties: {
            directory: {
              type: 'string',
              default: '.',
              description: 'Directory to search for backup files'
            },
            pattern: {
              type: 'string',
              default: '*.bak',
              description: 'Backup file pattern'
            }
          }
        }
      },
      {
        name: 'help',
        description: 'Get detailed help and examples for smalledit tools',
        inputSchema: {
          type: 'object',
          properties: {
            tool: {
              type: 'string',
              description: 'Tool name for help (e.g., "sed_edit", "perl_edit") or "all" for overview'
            }
          }
        }
      }
    ]
  };
});

src/index.ts:358-382 (helper)

Help content and examples for the sed_edit tool, stored in helpContent object.

  sed_edit: `sed_edit - Pattern-based file editing
===================================
Uses perl backend for cross-platform compatibility.

Examples:
  // Simple replacement
  sed_edit({ file: "config.json", pattern: "s/localhost/production/g" })
  
  // Delete lines containing pattern
  sed_edit({ file: "app.js", pattern: "$_ = '' if /console\\.log/" })
  
  // Preview changes first
  sed_edit({ file: "test.txt", pattern: "s/old/new/g", preview: true })
  
  // Edit without backup
  sed_edit({ file: "temp.txt", pattern: "s/a/b/g", backup: false })

Note: Actually uses perl internally for better compatibility.

WHEN NOT TO USE:
- Multi-line replacements
- Complex code modifications  
- JSON/YAML structure changes
→ Use filesystem:edit_file instead!
`,

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