解析路径名称 [英] Parsing a path name
问题描述
我正在使用一个服务器，它将为我提供文件的路径名，
在众多路径中。所以从getenv我可能得到/ home / myweb / page1但是，
当然，会有很多变化。我不确定如何沿着这条路走下去的最佳方式。我应该一次读一个字符
还是使用scanf？例如，
/ home / mypage / page1 / page1 / page2 / page2等问题可能会出现问题。
我还没有编程几年，所以我可以使用一些提示，
提示，链接和C函数。 tia
I''m working with a server that will provide me the pathname to a file,
among many paths. So from getenv I may get /home/myweb/page1 but, of
course, there will be many variations of that. I''m unsure of the best
way to go about following the path. Should I read one char at a time
or use scanf? The problem could occur with something like
/home/mypage/page1/page1/page2/page2, for example.
I have not been programming in a few years so I could use a few hints,
tips, links and C functions. tia
推荐答案
drhowarddrfine说：
drhowarddrfine said:
我正在工作使用服务器将为我提供文件的路径名，
在众多路径中。所以从getenv我可能得到/ home / myweb / page1但是，
当然，会有很多变化。我不确定如何沿着这条路走下去的最佳方式。我应该一次读一个字符
还是使用scanf？例如，
/ home / mypage / page1 / page1 / page2 / page2这样的问题可能会发生。
I''m working with a server that will provide me the pathname to a file,
among many paths. So from getenv I may get /home/myweb/page1 but, of
course, there will be many variations of that. I''m unsure of the best
way to go about following the path. Should I read one char at a time
or use scanf? The problem could occur with something like
/home/mypage/page1/page1/page2/page2, for example.
大概是你定义了路径作为一系列短步骤，每个步骤开始
带有/字符的
，并且跟随另一个这样的步骤，或者通过字符串的
结尾 。
所以分步解析：
#include< stdio.h>
#define MAX_STEP_LEN 256 / *在你的例子中，8会完成！ * /
int get_step（char * out，char ** cur，char sep，size_t max）
{
int rc = 0;
if（** cur！=''\'''）
{
* out ++ = ** cur ;
++ * cur;
--max;
while（最大0&& ** cur！ =''\ 0''&& ** cur！= sep）
{
* out ++ = ** cur;
++ * cur;
--max;
}
* out =''\ 0'';
rc = 1;
}
返回rc;
}
int main（无效）
{
char path [] =" / home / mypage / page1 / page1 / page2 / page2" ;;
char步[MAX_STEP_LEN] = {0};
char * curstep = path;
while（get_step（step，& curstep，''/' '，MAX_STEP_LEN））
{
printf（" [％s] \ n"，step）;
}
返回0;
}
输出：
[/ home ]
[/ mypage]
[/ page1]
[/ page1]
[/ page2]
[/ page2]
如果这样做你想要的，那很好。如果没有，它至少应该让你开始。
-
Richard Heathfield
Usenet是一个奇怪的地方 - dmr 29/7/1999
http://www.cpax.org.uk
电子邮件：rjh在上面的域名（但显然放弃了www）
Presumably you define "path" as "series of short steps, each of which begins
with a / character, and is followed either by another such step, or by the
end of the string".
So parse it in steps:
#include <stdio.h>
#define MAX_STEP_LEN 256 /* in your example, 8 would have done! */
int get_step(char *out, char **cur, char sep, size_t max)
{
int rc = 0;
if(**cur != ''\0'')
{
*out++ = **cur;
++*cur;
--max;
while(max 0 && **cur != ''\0'' && **cur != sep)
{
*out++ = **cur;
++*cur;
--max;
}
*out = ''\0'';
rc = 1;
}
return rc;
}
int main(void)
{
char path[] = "/home/mypage/page1/page1/page2/page2";
char step[MAX_STEP_LEN] = {0};
char *curstep = path;
while(get_step(step, &curstep, ''/'', MAX_STEP_LEN))
{
printf("[%s]\n", step);
}
return 0;
}
Output:
[/home]
[/mypage]
[/page1]
[/page1]
[/page2]
[/page2]
If that does what you want, great. If not, it should at least get you
started.
--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at above domain (but drop the www, obviously)
" ; drhowarddrfine" < ro ******* @ gmail.com写信息
news：11 ******************** @ e3g2000cwe。 googlegroup s.com ...
"drhowarddrfine" <ro*******@gmail.comwrote in message
news:11********************@e3g2000cwe.googlegroup s.com...
我正在使用一个服务器，它将为我提供文件的路径名，
之间很多路。所以从getenv我可能得到/ home / myweb / page1但是，
当然，会有很多变化。我不确定如何沿着这条路走下去的最佳方式。我应该一次读一个字符
还是使用scanf？例如，
/ home / mypage / page1 / page1 / page2 / page2这样的问题可能会发生。
I''m working with a server that will provide me the pathname to a file,
among many paths. So from getenv I may get /home/myweb/page1 but, of
course, there will be many variations of that. I''m unsure of the best
way to go about following the path. Should I read one char at a time
or use scanf? The problem could occur with something like
/home/mypage/page1/page1/page2/page2, for example.
你在谈论什么*问题*
你实际上在尝试做什么？
What *problem* are you talking about?
What is it that you are actually trying to do?
>
我几年没编程了所以我可以使用一些提示，
提示，链接和C功能。 tia
>
I have not been programming in a few years so I could use a few hints,
tips, links and C functions. tia
-
Fred L. Kleinschmidt
波音助理技术研究员
技术架构师，软件重用项目
--
Fred L. Kleinschmidt
Boeing Associate Technical Fellow
Technical Architect, Software Reuse Project
很难理解你想做什么 - 你可能想用
strtok来拆分你的字符串，用斜杠分隔
it is difficult to understand what you want to do - you might want to use
strtok to split up your string, delimited by slashes
这篇关于解析路径名称的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
