来一发Centos tailf下令 - 仓酷云

/*tailf.c--tailalogfileandthenfollowit*Created:TueJan915:49:211996byfaith@acm.org*Copyright1996,2003RickardE.Faith(faith@acm.org)**Permissionisherebygranted,freeofcharge,toanypersonobtaininga*copyofthissoftwareandassociateddocumentationfiles(the"Software"),*todealintheSoftwarewithoutrestriction,includingwithoutlimitation*therightstouse,copy,modify,merge,publish,distribute,sublicense,*and/orsellcopiesoftheSoftware,andtopermitpersonstowhomthe*Softwareisfurnishedtodoso,subjecttothefollowingconditions:**Theabovecopyrightnoticeandthispermissionnoticeshallbeincluded*inallcopiesorsubstantialportionsoftheSoftware.**THESOFTWAREISPROVIDED"ASIS",WITHOUTWARRANTYOFANYKIND,EXPRESSOR*IMPLIED,INCLUDINGBUTNOTLIMITEDTOTHEWARRANTIESOFMERCHANTABILITY,*FITNESSFORAPARTICULARPURPOSEANDNONINFRINGEMENT.INNOEVENTSHALL*THEAUTHORSORCOPYRIGHTHOLDERSBELIABLEFORANYCLAIM,DAMAGESOR*OTHERLIABILITY,WHETHERINANACTIONOFCONTRACT,TORTOROTHERWISE,*ARISINGFROM,OUTOFORINCONNECTIONWITHTHESOFTWAREORTHEUSEOR*OTHERDEALINGSINTHESOFTWARE.**less-Fandtail-fcauseadiskaccesseveryfiveseconds.This*programavoidsthisproblembywaitingforthefilesizetochange.*Hence,thefileisnotaccessed,andtheaccesstimedoesnotneedtobe*flushedbacktodisk.Thisissortofa"stealth"tail.*/#include<stdio.h>#include<stdlib.h>#include<unistd.h>#include<malloc.h>#include<sys/stat.h>//#include"nls.h"#define_(s)sstaticsize_tfilesize(constchar*filename){structstatsb;if(!stat(filename,&sb))returnsb.st_size;return0;}staticvoidtailf(constchar*filename,intlines){char**buffer;inthead=0;inttail=0;FILE*str;inti;if(!(str=fopen(filename,"r"))){fprintf(stderr,_("Cannotopen"%s"forread
"),filename);perror("");exit(1);}buffer=malloc(lines*sizeof(*buffer));for(i=0;i<lines;i++)buffer[i]=malloc(BUFSIZ+1);while(fgets(buffer[tail],BUFSIZ,str)){if(++tail>=lines){tail=0;head=1;}}if(head){for(i=tail;i<lines;i++)fputs(buffer[i],stdout);for(i=0;i<tail;i++)fputs(buffer[i],stdout);}else{for(i=head;i<tail;i++)fputs(buffer[i],stdout);}fflush(stdout);for(i=0;i<lines;i++)free(buffer[i]);free(buffer);}intmain(intargc,char**argv){charbuffer[BUFSIZ];size_tosize,nsize;FILE*str;constchar*filename;intcount;//setlocale(LC_ALL,"");//bindtextdomain(PACKAGE,LOCALEDIR);//textdomain(PACKAGE);if(argc!=2){fprintf(stderr,_("Usage:tailflogfile
"));exit(1);}filename=argv[1];tailf(filename,10);for(osize=filesize(filename);;){nsize=filesize(filename);if(nsize!=osize){if(!(str=fopen(filename,"r"))){fprintf(stderr,_("Cannotopen"%s"forread
"),filename);perror(argv[0]);exit(1);}if(!fseek(str,osize,SEEK_SET))while((count=fread(buffer,1,sizeof(buffer),str))>0)fwrite(buffer,1,count,stdout);fflush(stdout);fclose(str);osize=nsize;}usleep(250000);/*250mS*/}return0;}

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