我想使用 sed 将 data.txt 转换为方案列表，格式如下：
- 具有相同起始编号的每一行都将被解析和组合，如下所示：
数据.txt
1,{},344.233
1,{2},344.197
2,{16},290.281
2,{18},289.093
3,{1},220.896
foo.scm
(define v1 '(1 (() 344.233) ((2) 344.197))) ;; this is for first two lines starting with 1
(define v2 '(2 ((16) 290.281) ((18) 289.093))) ;; ... 2
(define v3 '(3 (() 237.558))) ;; ... 3
我对方案一无所知，所以我可能会在 awk 而不是 sed 中执行此操作。
[ghoti@pc ~]$ cat data.txt
1,{},344.233
1,{2},344.197
2,{16},290.281
2,{18},289.093
3,{1},220.896
[ghoti@pc ~]$ cat doit.awk
#!/usr/bin/awk -f
BEGIN {
FS=",";
last1=1;
}
$1 != last1 {
printf("(define v%.0f '(%.0f %s))\n", last1, last1, substr(sect,2));
last1=$1; sect="";
}
{
gsub(/[^0-9]/,"",$2);
sect=sprintf("%s ((%s) %s)", sect, $2, $3);
}
END {
printf("(define v%.0f '(%.0f %s))\n", last1, last1, substr(sect,2));
}
[ghoti@pc ~]$ ./doit.awk data.txt
(define v1 '(1 (() 344.233) ((2) 344.197)))
(define v2 '(2 ((16) 290.281) ((18) 289.093)))
(define v3 '(3 ((1) 220.896)))
[ghoti@pc ~]$
它当然可以写得更紧密，但这可以完成工作。
更新：（根据评论）
[ghoti@pc ~]$ tail -1 data.txt
3,{1,3,4},220.896
[ghoti@pc ~]$ diff -u doit.awk doitnew.awk
--- doit.awk 2012-05-30 00:38:34.549680376 -0400
+++ doitnew.awk 2012-05-30 00:38:52.893810815 -0400
@@ -10,8 +10,15 @@
last1=$1; sect="";
}
+$2 !~ /}$/ {
+ while ($2 !~ /}$/) {
+ pos=match($0, /,[0-9,]+}/);
+ $0=substr($0, 0, pos-1) " " substr($0, pos+1);
+ }
+}
+
{
- gsub(/[^0-9]/,"",$2);
+ gsub(/[^0-9 ]/,"",$2);
sect=sprintf("%s ((%s) %s)", sect, $2, $3);
}
[ghoti@pc ~]$ ./doitnew.awk data.txt
(define v1 '(1 (() 344.233) ((2) 344.197)))
(define v2 '(2 ((16) 290.281) ((18) 289.093)))
(define v3 '(3 ((1 3 4) 220.896)))
[ghoti@pc ~]$
这里发生了什么？
在我们添加的新块中，测试第二个字段是否以}. 如果没有，我们将循环直到它出现。对于循环的每次运行，我们将删除 之前的逗号}，用空格替换它。
有时，蛮力有效。:-P
在球拍（又名计划）中：
#lang racket
;; parse a line (we will join them later)
(define (line-parse l)
(match (regexp-match #px"([0-9]+),\\{([0-9,]*)\\},([0-9.]+)" l)
[(list dc first-num bracket-nums rest)
(list (string->number first-num)
(match bracket-nums
["" empty]
[else (map string->number
(regexp-split #px"," bracket-nums))])
(string->number rest))]
[else
(error "unexpected line format in line: ~s\n" l)]))
;; join together lines that start with the same number
(define (join-lines lines)
(cond [(empty? lines) empty]
[else (join-lines-of-n (first (first lines))
lines
empty)]))
;; gather together lines starting with 'n':
(define (join-lines-of-n n lines accum)
(cond [(empty? lines)
(list (cons n (reverse accum)))]
[(equal? (first (first lines)) n)
(join-lines-of-n n (rest lines) (cons (rest (first lines))
accum))]
[else
(cons (cons n (reverse accum))
(join-lines lines))]))
(define (dress-up line)
(format "~a\n" `(define ,(format "v~s" (first line))
',line)))
(display
(apply
string-append
(map dress-up
(join-lines
(map line-parse
(sequence->list (in-port read-line)))))))
将它保存为 rewrite.rkt，像这样运行它：
oiseau:/tmp clements> racket ./rewrite.rkt < foo.txt
(define v1 (quote (1 (() 344.233) ((2) 344.197))))
(define v2 (quote (2 ((16) 290.281) ((18) 289.093))))
(define v3 (quote (3 ((1) 220.896) ((4 5) 2387.278))))
...请注意，我在输入示例中添加了 {4,5} 行来测试您的扩展。
另外，请注意输出使用 (quote ...) 而不是 '(...)。这“应该可以正常工作”；也就是说，Scheme 阅读器为这两种形式生成相同的输出，并且生成的文件应该可以作为方案输入正常工作。
如果这是我的代码，我想我不会跳 (define v1 ...) 跳舞，而只是把它写成一大段数据，一个方案/球拍程序可以通过一次“读取”来吞食，但这是你的选择，不是我的。此外，您的规范中存在一些歧义：初始索引的唯一性；也就是说，您可能会“返回”到较早的行号。例如，当给定这个输入文件时，输出应该是什么：
3,{1},1.0
4,{1},1.0
3,{1},1.0
?
另外，请注意，我删除了所有测试用例以使其看起来更短/更漂亮:)。
编辑：哦！相反，以这种方式收集线条。它实际上会慢一点，但它读起来更好：
#lang racket
;; parse a line (we will join them later)
(define (line-parse l)
(match (regexp-match #px"([0-9]+),\\{([0-9,]*)\\},([0-9.]+)" l)
[(list dc first-num bracket-nums rest)
(list (string->number first-num)
(match bracket-nums
["" empty]
[else (map string->number
(regexp-split #px"," bracket-nums))])
(string->number rest))]
[else
(error "unexpected line format in line: ~s\n" l)]))
;; does the line start with the number k?
(define ((starts-with k) l) (equal? (first l) k))
;; join together lines starting with the same thing:
(define (join-lines lines)
(for/list ([k (remove-duplicates (map first lines))])
(cons k (map rest (filter (starts-with k) lines)))))
(define (dress-up line)
(format "~a\n" `(define ,(format "v~s" (first line))
',line)))
(display
(apply
string-append
(map dress-up
(join-lines
(map line-parse
(sequence->list (in-port read-line)))))))
这可能对您有用（GNU sed）：
sed ':a;$!N;s/^\(\([^,])*\).*\)\n\2/\1/;ta;h;x;s/\n.*//;s/,{\([^}]*\)},\([^,]\+\)/ ((\1) \2)/g;s/,/ /g;s/^\([^ ]*\).*/(define v\1 '\''(&)) ;;...\1/p;x;D' file
解释：
:a;$!N;s/^\(\([^,])*\).*\)\n\2/\1/;tahxs/\n.*//s/,{\([^}]*\)},\([^,]\+\)/ ((\1) \2)/g,的 '。s/,/ /gs/^\([^ ]*\).*/(define v\1 '\''(&)) ;;...\1/pxD