Scheme 语言 实战 批量重命名文件的命令行工具开发

Scheme^【1】 语言实战：批量重命名^【2】文件的命令行工具^【3】开发

Scheme 语言是一种函数式编程^【4】语言，以其简洁、优雅和强大的表达能力而著称。在命令行工具的开发中，Scheme 语言可以发挥其独特的优势，帮助我们实现高效、灵活的脚本编写^【5】。本文将围绕使用 Scheme 语言开发一个批量重命名文件的命令行工具，探讨相关技术实现。

Scheme 语言简介

Scheme 语言是一种函数式编程语言，起源于 1970 年代的 Lisp 语言。它具有以下特点：

- 函数式编程：Scheme 语言强调函数作为程序的基本构建块，通过函数组合实现复杂逻辑。
- 简洁语法：Scheme 语言的语法简洁，易于阅读和理解。
- 动态类型^【6】：Scheme 语言是动态类型的语言，变量不需要声明类型。
- 高阶函数^【7】：Scheme 语言支持高阶函数，可以传递函数作为参数或返回函数。

批量重命名文件工具的需求分析^【8】

在文件管理^【9】中，批量重命名文件是一个常见的操作。以下是一些批量重命名文件工具的需求：

- 支持多种文件格式：工具应支持多种文件格式的重命名。
- 灵活的重命名规则：用户可以自定义重命名规则，如添加前缀、后缀、修改文件名等。
- 批量处理^【10】：工具应支持批量处理多个文件。
- 命令行界面^【11】：提供命令行界面，方便用户通过命令行操作。

Scheme 语言开发批量重命名文件工具

1. 环境搭建

确保你的计算机上安装了 Scheme 解释器。常用的 Scheme 解释器有 Guile^【12】、Racket^【13】 等。以下以 Racket 为例进行说明。

bash
安装 Racket
sudo apt-get install racket


2. 设计工具架构

根据需求分析，我们可以将工具分为以下几个模块^【14】：

- 文件读取模块^【15】：读取指定目录下的文件列表。
- 重命名规则解析模块^【16】：解析用户输入的重命名规则。
- 文件重命名模块：根据解析出的规则重命名文件。
- 命令行界面模块：处理用户输入的命令，调用其他模块完成操作。

3. 编写代码

以下是一个简单的批量重命名文件工具的代码示例：

```scheme
(define (main)
(displayln "Welcome to the Batch Rename Tool!")
(displayln "Please enter the directory path: ")
(let ([dir (read-line)])
(displayln "Please enter the rename rule (e.g., "prefix_.txt"): ")
(let ([rule (read-line)])
(rename-files dir rule))))

(define (rename-files dir rule)
(let ([files (list-directory dir)])
(foreach ([file files])
(let ([new-name (rename-file file rule)])
(rename-file file new-name)))))

(define (list-directory dir)
(let ([files (os/list-dir dir)])
(filter (lambda ([file]) (string? file)) files)))

(define (rename-file file rule)
(let ([name (file-name file)])
(let ([ext (file-extension name)])
(let ([new-name (string-append (substring rule 0 (- (length rule) (length ext))) ext)])
(string-append<sup>【17】</sup> (file-directory file) new-name)))))

(define (file-name file)
(substring<sup>【18】</sup> file (string-index<sup>【19】</sup> file /) (- (length<sup>【20】</sup> file) (string-index file .))))

(define (file-extension file)
(substring file (+ (string-index file .)) (length file)))

(define (file-directory file)
(substring file 0 (- (length file) (length (file-name file)))))

(define (os/list-dir dir)
(os/exec (string-append "ls " dir)))

(define (os/exec cmd)
(let ([proc (os/process-open cmd)])
(let ([output (os/process-read proc)])
(os/process-close proc)
output)))

(define (substring str start end)
(let ([len (length str)])
(if (or (> start len) (> end len))
(error<sup>【21】</sup> "Substring index out of range")
(string-append (substring str 0 start) (substring str end len)))))

(define (string-append . strings)
(apply<sup>【22】</sup> string-append strings))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1)))

(define (rename-file file new-name)
(os/exec (string-append "mv " file " " new-name)))

(define (os/process-open cmd)
(os/exec (string-append "bash -c '" cmd "'")))

(define (os/process-read proc)
(let ([output (os/exec (string-append "cat number (substring output 0 (- (length output) 1)))))

(define (os/process-fd proc)
(let ([output (os/exec (string-append "echo $!" (os/process-id proc)))]
(substring output 0 (- (length output) 1))))

(define (string->number<sup>【23】</sup> str)
(let ([num (string->symbol str)])
(symbol->number<sup>【24】</sup> num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string<sup>【25】</sup> sym)
(string-append (string->list<sup>【26】</sup> sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons<sup>【27】</sup> (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1)))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])
(if (or (= index -1) (= index 0))
(if (= sub (substring str 0 1))
0
-1)
(+ index 1)))
-1))

(define (string-append . strings)
(apply string-append strings))

(define (string->number str)
(let ([num (string->symbol str)])
(symbol->number num)))

(define (symbol->number sym)
(let ([num (string->number (symbol->string sym))])
(if (or (null? num) (not (number? num)))
(error "Invalid number")
num)))

(define (symbol->string sym)
(string-append (string->list sym)))

(define (string->list str)
(let ([len (length str)])
(if (= len 0)
'()
(cons (string->list (substring str 1)) (list (string->list (substring str 0 1)))))))

(define (string-index str sub)
(let ([len (length str)])
(if (> len 0)
(let ([index (string-index (substring str 1) sub)])