main 함수의 기본 프로토타입은 int main(int argc, char *argv[]) 이다.
물론 귀찮아서 void main()으로 주로 쓰긴 하지만, 인자를 받기 위해서는 저 프로토타입을 써야 한다.
아무튼 막상 인자로 받다가 그 인자를 만들어 내려니 자꾸만 안되서 머리를 데굴데굴 굴려봤다.
Besides, unix way is to be ascetic and elegant, avoiding putting messy and slow algorithms under the hood, and filecopy is definitely slow ( you want syscall with fast filecopy - great, here's hardlink for you ).
생각해보니.. UNIX의 설계 철학중 simple is beautiful이 근간이 되어 있다는게 생각이 났다.
cp() 가 빈번하게 사용될지라도, 느린 함수이고(최소한 fopen/fread/fwrite/fclose 4개의 함수를 사용한다)
이러한 복잡한 함수는 단순함의 철학에 위배가 되기에 많이 사용함에도 불구하고
cp() 라는 함수가 존재하지 않는것 같다.
그래도...
rename() remove() 이런건 있으면서 cp()가 없다는 건 웬지 억울한 느낌?
int cp(char *dest, char *sour)
{
FILE *dst;
FILE *src;
int readlen;
unsigned char buf[1024];
A regular expression is a pattern that describes a set of strings.
Regular expressions are constructed analogously to arithmetic expres-
sions, by using various operators to combine smaller expressions.
grep understands three different versions of regular expression syntax:
"basic," "extended," and "perl." In GNU grep, there is no difference
in available functionality using either of the first two syntaxes. In
other implementations, basic regular expressions are less powerful.
The following description applies to extended regular expressions; dif-
ferences for basic regular expressions are summarized afterwards. Perl
regular expressions add additional functionality, but the implementa-
tion used here is undocumented and is not compatible with other grep
implementations.
The fundamental building blocks are the regular expressions that match
a single character. Most characters, including all letters and digits,
are regular expressions that match themselves. Any metacharacter with
special meaning may be quoted by preceding it with a backslash.
A bracket expression is a list of characters enclosed by [ and ]. It
matches any single character in that list; if the first character of
the list is the caret ^ then it matches any character not in the list.
For example, the regular expression [0123456789] matches any single
digit.
Within a bracket expression, a range expression consists of two charac-
ters separated by a hyphen. It matches any single character that sorts
between the two characters, inclusive, using the locale's collating
sequence and character set. For example, in the default C locale,
[a-d] is equivalent to [abcd]. Many locales sort characters in dictio-
nary order, and in these locales [a-d] is typically not equivalent to
[abcd]; it might be equivalent to [aBbCcDd], for example. To obtain
the traditional interpretation of bracket expressions, you can use the
C locale by setting the LC_ALL environment variable to the value C.
Finally, certain named classes of characters are predefined within
bracket expressions, as follows. Their names are self explanatory, and
they are [:alnum:], [:alpha:], [:cntrl:], [:digit:], [:graph:],
[:lower:], [:print:], [:punct:], [:space:], [:upper:], and [:xdigit:].
For example, [[:alnum:]] means [0-9A-Za-z], except the latter form
depends upon the C locale and the ASCII character encoding, whereas the
former is independent of locale and character set. (Note that the
brackets in these class names are part of the symbolic names, and must
be included in addition to the brackets delimiting the bracket list.)
Most metacharacters lose their special meaning inside lists. To
include a literal ] place it first in the list. Similarly, to include
a literal ^ place it anywhere but first. Finally, to include a literal
- place it last.
The period . matches any single character. The symbol \w is a synonym
for [[:alnum:]] and \W is a synonym for [^[:alnum]].
The caret ^ and the dollar sign $ are metacharacters that respectively
match the empty string at the beginning and end of a line. The symbols
\< and \> respectively match the empty string at the beginning and end
of a word. The symbol \b matches the empty string at the edge of a
word, and \B matches the empty string provided it's not at the edge of
a word.
A regular expression may be followed by one of several repetition oper-
ators:
? The preceding item is optional and matched at most once.
* The preceding item will be matched zero or more times.
+ The preceding item will be matched one or more times.
{n} The preceding item is matched exactly n times.
{n,} The preceding item is matched n or more times.
{n,m} The preceding item is matched at least n times, but not more
than m times.
Two regular expressions may be concatenated; the resulting regular
expression matches any string formed by concatenating two substrings
that respectively match the concatenated subexpressions.
Two regular expressions may be joined by the infix operator |; the
resulting regular expression matches any string matching either subex-
pression.
Repetition takes precedence over concatenation, which in turn takes
precedence over alternation. A whole subexpression may be enclosed in
parentheses to override these precedence rules.
The backreference \n, where n is a single digit, matches the substring
previously matched by the nth parenthesized subexpression of the regu-
lar expression.
In basic regular expressions the metacharacters ?, +, {, |, (, and )
lose their special meaning; instead use the backslashed versions \?,
\+, \{, \|, \(, and \).
Traditional egrep did not support the { metacharacter, and some egrep
implementations support \{ instead, so portable scripts should avoid {
in egrep patterns and should use [{] to match a literal {.
GNU egrep attempts to support traditional usage by assuming that { is
not special if it would be the start of an invalid interval specifica-
tion. For example, the shell command egrep '{1' searches for the two-
character string {1 instead of reporting a syntax error in the regular
expression. POSIX.2 allows this behavior as an extension, but portable
scripts should avoid it.
The handle for a specified key should not be used after it has been
closed, because it will no longer be valid. Key handles should not be
left open any longer than necessary.
The
RegCloseKey function does not necessarily write
information to the registry before returning; it can take as much as
several seconds for the cache to be flushed to the hard disk. If an
application must explicitly write registry information to the hard
disk, it can use the RegFlushKey function.
RegFlushKey, however, uses many system resources and should be called only when necessary.
Run-Time Library Reference _pgmptr, _wpgmptr
The path of the executable file. Deprecated; use _get_pgmptr and _get_wpgmptr.
Variable
Required header
Compatibility
_pgmptr, _wpgmptr
<stdlib.h>
Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium
Edition, Windows NT 4.0, Windows 2000, Windows XP Home Edition, Windows
XP Professional, Windows Server 2003, Windows Server 2003
