Python

Original title: Q: There is a.txt file, the contents of which are as follows 1234569 abcABCabc requires awk to print out the following results 987654321 cbaCBAcba A: shell: [root@vps tmp]# rev a.txt 9654321 cbaCBAcbaperl: [root@vps tmp]# perl -nle ‘print scalar reverse $_;’ a.txt 9654321 cbaCBAcbaawk ： [root@vps tmp]# awk ‘{num=split($0,arr,””);for(i=num;i>0;i–){printf arr[i];if(i==1) {printf “\n”}}}’ a.txt 9654321 cbaCBAcbaphp: [root@vps tmp]# php -r ‘$fp=fopen(“a.txt”,”r”); while(! feof($fp)){ echo strrev(fgets($fp,999));} echo “\n”;;’ 9654321 cbaCBAcbased: [root@vps tmp]# sed ‘/\n/!G ;s/\(.\)\(.*\n\)/&\2\1/;//D;s/.//’ a.txt 9654321 cbaCBAcba python: (one of the methods) >>> arr=’hello’>>>arr[::-1]‘olleh’ (Method 2) >>> str=’hello’>>> tmp=”>>> for s in reversed(str):… tmp+=s…>> > print tmpolleh reverse.h#ifndef _reverse_hint getLine(char s[],int limit);void reverse(char s[]);#endif int getLine(char s[],int limit){ int c,i ; for(i =0; ireverse.c#include “stdio.h”#include “/Users/chenqing/tmp/reverse.h”#define MAXLINE 1000/* reverse a string use c langusge*/int main(void){ int len; char line[MAXLINE]; if((len = getLine(line,MAXLINE)) > 0){ reverse(line); printf( “%s”,line); } return 0;} gcc reverse.c -o reverseQing:tmp chenqing$ echo “ChinaCache” |./reverseehcaCanihC The above is an example of using these implementations to realize string reversal under the terminal command line, haha, In fact, it is still cool to implement perl.