mcp-ssh-tool

Instructions

Implementation Reference

• src/ensure.ts:234-324 (handler)

  The handler function `ensureLinesInFile` which verifies existence of lines in a file and appends them if they are missing.

  export async function ensureLinesInFile(
    sessionId: string,
    filePath: string,
    lines: string[],
    createIfMissing: boolean = true,
    sudoPassword?: string
  ): Promise<LinesInFileResult> {
    logger.debug('Ensuring lines in file', { sessionId, filePath, lineCount: lines.length });
  
    try {
      const osInfo = await sessionManager.getOSInfo(sessionId);
      let fileContent = '';
      let fileExists = false;
  
      // Check if file exists and read its content
      if (await pathExists(sessionId, filePath)) {
        fileExists = true;
        fileContent = await readFile(sessionId, filePath);
      } else if (!createIfMissing) {
        throw createFilesystemError(
          `File ${filePath} does not exist and createIfMissing is false`
        );
      }
  
      // Check which lines are missing
      const existingLines = fileContent.split('\n');
      const missingLines: string[] = [];
  
      for (const line of lines) {
        if (!existingLines.includes(line)) {
          missingLines.push(line);
        }
      }
  
      if (missingLines.length === 0) {
        logger.info('All lines already exist in file', { sessionId, filePath });
        return {
          ok: true,
          added: 0
        };
      }
  
      // Add missing lines
      const newContent = fileExists
        ? fileContent + '\n' + missingLines.join('\n')
        : missingLines.join('\n');
  
      // Write file (may need sudo)
      try {
        await writeFile(sessionId, filePath, newContent);
      } catch (error) {
        if (sudoPassword) {
          // Try with sudo by writing to temp file and moving
          const tempDir = resolveRemoteTempDir(osInfo);
          const baseTempDir = tempDir.replace(/\/+$/, '');
          const tempFile = `${baseTempDir}/ssh-mcp-${Date.now()}.tmp`;
          await writeFile(sessionId, tempFile, newContent);
  
          const moveResult = await execSudo(
            sessionId,
            `mv ${tempFile} ${filePath}`,
            sudoPassword
          );
  
          if (moveResult.code !== 0) {
            throw createFilesystemError(
              `Failed to move temporary file to ${filePath}`,
              'Check file permissions and sudo access'
            );
          }
        } else {
          throw error;
        }
      }
  
      logger.info('Lines added to file successfully', {
        sessionId,
        filePath,
        added: missingLines.length
      });
  
      return {
        ok: true,
        added: missingLines.length
      };
  
    } catch (error) {
      logger.error('Failed to ensure lines in file', { sessionId, filePath, error });
      throw error;
    }
  }