Is there a way make the lex program match multiple line?
Hi community,
I am making a config program, use the lex program to analyse input.
/*
config.l
The lex rule file for toysql
Wen Yi
*/
%option noyywrap
%{
#include <string.h>
#include <stdlib.h>
%}
%%
-[0-9]+.[0-9]+|[0-9]+.[0-9]+|-[0-9]+|[0-9]+ { printf("Number = %lf\n", atof(yytext)); }
[a-zA-Z_0-9]+ { printf("Token = %s\n", yytext); }
['].+['] {
yytext[yyleng - 1] = '\0';
memmove(yytext, yytext + 1, yyleng - 1);
printf("String = %s\n", yytext);
}
; {}
. { printf("Anything: '%s'\n", yytext); }
%%
int main()
{
yylex();
return 0;
}
But when I try to run it:
[beginnerc@bogon config]$ ./a.out
'This is a single line string'
String = This is a single line string
'This is a multiple line string
Anything: '''
Token = This
Anything: ' '
Token = is
Anything: ' '
Token = a
Anything: ' '
Token = multiple
Anything: ' '
Token = line
Anything: ' '
Token = string
Can someone give me some advice to make the ['].+['] match multiple string?
Thanks in advance!
Yours,
Wen Yi
"=?ISO-8859-1?B?V2VuIFlp?=" <896634148@qq.com> writes:
Can someone give me some advice to make the ['].+['] match multiple string?
You should check the flex manual, but it's likely that "." doesn't
match newline. Another problem with this pattern is that "."
*does* match "'", so it's ambiguous what will happen with quotes.
You probably need something closer to [']([^']|\n)[']
regards, tom lane
I rewrite, and I think the [']([^']|\n)['] should be [']([^']|\n)+[']
Thanks very much!
Yours,
Wen Yi.
------------------ Original ------------------
From: "Tom Lane" <tgl@sss.pgh.pa.us>;
Date: Sun, Jun 18, 2023 09:50 AM
To: "Wen Yi"<896634148@qq.com>;
Cc: "pgsql-general"<pgsql-general@lists.postgresql.org>;
Subject: Re: Is there a way make the lex program match multiple line?
"=?ISO-8859-1?B?V2VuIFlp?=" <896634148@qq.com> writes:
> Can someone give me some advice to make the ['].+['] match multiple string?
You should check the flex manual, but it's likely that "." doesn't
match newline. Another problem with this pattern is that "."
*does* match "'", so it's ambiguous what will happen with quotes.
You probably need something closer to [']([^']|\n)[']
regards, tom lane