perl中while修饰符/c参数

[oracle@localhost ~]$ cat tmpperl01
#!/usr/bin/perl
$_ = "The year 1752 lost 10 days on the 3rd of September";
while (/(d+)/g)
{
print pos($_),"n";
}
print pos($_)."---","n";
while (/e/g)
{
print pos($_),"n";
}

print pos($_)."---","n";

[oracle@localhost ~]$ cat tmpperl02
#!/usr/bin/perl
$_ = "The year 1752 lost 10 days on the 3rd of September";
while (/(d+)/cg)
{
print pos($_),"n";
}
print pos($_)."---","n";
while (/e/cg)
{
print pos($_),"n";

[oracle@localhost ~]$ ./tmpperl01
13
21
35
---
3
6
33
43
46
49
---
[oracle@localhost ~]$ ./tmpperl02
13
21
35
35---
43
46
49
49---

#增加/c修饰符在匹配失败后不重置pos的位置