我有这样的文件：
public class Presidents
{
public int presidentNumber;
public String presidentName;
public int startingYear;
public int endingYear;
public Presidents(int PresidentNumber, String NameOfPresident, int StartingYear, int EndingYear)
{
this.presidentNumber = PresidentNumber;
this.presidentName = NameOfPresident;
this.startingYear = StartingYear;
this.endingYear = EndingYear;
}
public Presidents() {
}
public Presidents [] PresidentList ()
{
Presidents [] president = new Presidents [45];
president [0] = Presidents(1, "George Washington", 1789, 1797);
president [1] = Presidents(2, "John Adams", 1797, 1801);
president [2] = Presidents(3, "Thomas Jefferson", 1801, 1809);
president [3] = Presidents(4, "James Madison", 1809, 1817);
president [4] = Presidents(5, "James Monroe", 1817, 1825);
president [5] = Presidents(6, "John Quincy Adams", 1825, 1829);
president [6] = Presidents(7, "Andrew Jackson", 1829, 1837);
president [7] = Presidents(8, "Martin Van Buren", 1837, 1841);
president [8] = Presidents(9, "William Henry Harrison", 1841, 1841);
president [9] = Presidents(10, "John Tyler", 1841, 1845);
president [10] = Presidents(11, "James K. Polk", 1845, 1849);
president [11] = Presidents(12, "Zachary Taylor", 1849, 1850);
president [12] = Presidents(13, "Millard Fillmore", 1850, 1853);
president [13] = Presidents(14, "Franklin Pierce", 1853, 1857);
president [14] = Presidents(15, "James Buchanan", 1857, 1861);
president [15] = Presidents(16, "Abraham Lincoln", 1861, 1865);
president [16] = Presidents(17, "Andrew Johnson", 1865, 1869);
president [17] = Presidents(18, "Ulysses S. Grant", 1869, 1877);
president [18] = Presidents(19, "Rutherford B. Hayes", 1877, 1881);
president [19] = Presidents(20, "James A. Garfield", 1881, 1881);
president [20] = Presidents(21, "Chester A. Arthur", 1881, 1885);
president [21] = Presidents(22, "Grover Cleveland", 1885, 1889);
president [22] = Presidents(23, "Benjamin Harrison", 1889, 1893);
president [23] = Presidents(24, "Grover Cleveland", 1893, 1897);
president [24] = Presidents(25, "William McKinley", 1897, 1901);
president [25] = Presidents(26, "Theodore Roosevelt", 1901, 1909);
president [26] = Presidents(27, "William Howard Taft", 1909, 1913);
president [27] = Presidents(28, "Woodrow Wilson", 1913, 1921);
president [28] = Presidents(29, "Warren G. Harding", 1921, 1923);
president [29] = Presidents(30, "Calvin Coolidge", 1923, 1929);
president [30] = Presidents(31, "Herbert Hoover", 1929, 1933);
president [31] = Presidents(32, "Franklin D. Roosevelt", 1933, 1945);
president [32] = Presidents(33, "Harry S. Truman", 1945, 1953);
president [33] = Presidents(34, "Dwight D. Eisenhower", 1953, 1961);
president [34] = Presidents(35, "John F. Kennedy", 1961, 1963);
president [35] = Presidents(36, "Lyndon B. Johnson", 1963, 1969);
president [36] = Presidents(37, "Richard Nixon", 1969, 1974);
president [37] = Presidents(38, "Gerald Ford", 1974, 1977);
president [38] = Presidents(39, "Jimmy Carter", 1977, 1981);
president [39] = Presidents(40, "Ronald Reagan", 1981, 1989);
president [40] = Presidents(41, "George H. W. Bush", 1989, 1993);
president [41] = Presidents(42, "Bill Clinton", 1993, 2001);
president [42] = Presidents(43, "George W. Bush", 2001, 2009);
president [43] = Presidents(44, "Barack Obama", 2009, 2017);
president [44] = Presidents(45, "Donald Trump", 2017, 2018);
return president;
}
private Presidents Presidents(int i, String string, int j, int k) {
return Presidents (i, string, j, k);
}
}
import java.util.Scanner;
import java.util.Random;
public class PresidentsQuiz {
public static void main (String [] args)
{
System.out.println("Do you know the 45 presidents of the United States? Enter a number between 1 and 45");
Scanner kb = new Scanner (System.in);
int input = kb.nextInt();
while (input < 1 || input > 45)
{
System.out.println("Enter a number between 1 and 45");
input = kb.nextInt();
}
Presidents president = new Presidents ();
Presidents [] presidentList = president.PresidentList();
System.out.println(presidentList [0]);
kb.close();
}
}
我想要输出：
[host]$ cat /tmp/data
Breakfast 1
Lunch 1
Dinner 1
Dinner 1
Dinner 1
Lunch 1
Lunch 1
Dinner 1
如何使用awk / sed命令行脚本来做到这一点？
执行以下命令后，我得到了：
Breakfast 1
Lunch 3
Dinner 4
我现在不知道如何添加这些数字。
答案 0 :(得分：1)
awk '{a[$1]+=$2} END{for(i in a){print i, a[i]}}' /tmp/data
Dinner 4
Breakfast 1
Lunch 3
答案 1 :(得分：1)
请尝试以下操作，它将按照输入文件中第1个字段的输入顺序输出。
awk '!a[$1]++{b[++count]=$1} {c[$1]++} END{for(i=1;i<=count;i++){print b[i],c[b[i]]}}' Input_file
输出如下。
Breakfast 1
Lunch 3
Dinner 4
说明： 现在也添加了上述代码的说明。
awk '
!a[$1]++{ ##Checking condition if current lines first field is having only 1 count in array a then do following.
b[++count]=$1 ##Creating an array named b whose index is variable count whose value is increasing number by 1 and value is $1.
}
{
c[$1]++ ##Creating an array named c whose index is $1 with increment value by 1.
}
END{ ##Starting END block of awk code here.
for(i=1;i<=count;i++){ ##Starting a for loop from i=1 to till value of count here.
print b[i],c[b[i]] ##Printing value of array b whose index is variable i and printing value of array c whose index is value of array b.
}
}' Input_file ##Mentioning Input_file name here.
答案 2 :(得分：1)
由于每行输入的数字始终为1，因此您可以忽略它：
$ sort file | uniq -c | awk '{print $2, $1}'
Breakfast 1
Dinner 4
Lunch 3
或按出现次数排序：
$ sort file | uniq -c | sort -n | awk '{print $2, $1}'
Breakfast 1
Lunch 3
Dinner 4