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f <- function(start_time) { start_time <- as.POSIXct(start_time) dt <- difftime(Sys.time(), start_time, units="secs") # Since you only want the H:M... 阅读全文
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cat > WHAT_EVER_YOU_WANT.sh#!/usr/bin/ksh#memory calculatorum=`svmon -G | head -2|tail -1| awk {'print $3'}`um=`expr $um / 256`tm=`lsattr -El sys0 -a 阅读全文
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INSERT INTO table (a,b,c) VALUES (1,2,3) ON DUPLICATE KEY UPDATE c=c+1;INSERT 中 ON DUPLICATE KEY UPDATE的使用如果指定了ON DUPLICATE KEY UPDATE，并且插入行后会导致在一个UN... 阅读全文
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string1.equals(string2) 比较字符串 substring()它有两种形式，第一种是：String substring(int startIndex)第二种是：String substring(int startIndex,int endIndex) 注意：从位置0开始，包含st 阅读全文
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int iValue = new Integer(strValue).intValue();String str = intObj.toString();int number = Integer.parseInt(str);public static Object read(String value... 阅读全文
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use Time::HiRes qw(time);use POSIX qw(strftime);my $t = time;my $date = strftime "%Y%m%d %H:%M:%S", localtime $t;$date .= sprintf ".%03d", ($t-int($t) 阅读全文
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my $filename='/tmp/tmp.txt';open my $fh, '>', $filename;my $fd = fileno $fh;print readlink("/proc/$$/fd/$fd"); 阅读全文
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Perl File Handling: open, read, write and close files # Opening files Solution 1: Opening a file in perl open FILE, "filename.txt" or die $!; # read o 阅读全文
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Arithmetic OperatorsOperatorDescription+addition-subtraction*multiplication/division^ or ** exponentiationx %% y modulus (x mod y) 5%%2 is 1x %/% y in... 阅读全文
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$ echo $((20.0/7))$ zcalc$ bc <<< 20+5/2$ bc <<< 'scale=4;20+5/2'$ expr 20 + 5$ calc 2 + 4$ node -pe 20+5/2 # Uses the power of JavaScript, e.g. : no... 阅读全文