shell入门25-awk实践

今天差不多敲打了一天，对awk有新的认识，感觉都是另一个shell了，知识点很多。

一，理论知识

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二，实践

  862  awk -F: '$3<=10' /etc/passwd
  863  awk -F: '$3>100' /etc/passwd
  864  awk -F: '$3<=10{print $1}' /etc/passwd
  865  awk 'NR==4' /etc/passwd
  866  awk -F: '$3>1&&$3<5' /etc/passwd
  867  awk -F: '$3==1&&$3==5' /etc/passwd
  868  awk -F: '$3==1||$3==5' /etc/passwd
  869  awk 'BEGIN{print "OK"}'
  870  awk -F: 'BEGIN{print "用户名 UID 解释器"} \'
  871  awk -F: 'BEGIN{print "用户名 UID 解释器"} \
  872  {print $1,$3,$7} \
  873  END {print "总计有"NR"个帐户."}' /etc/passwd
  874  awk -F: 'BEGIN{print "用户名 UID 解释器"} \
  875  {print $1,$3,$7} \
  876  END {print "总计有"NR"个帐户."}' /etc/passwd | column -t
  877  awk 'BEGIN{print 2**3}'
  878  awk 'BEGIN{print 10-4}'
  879  awk 'BEGIN{x=8;y=2;print x*y}'
  880  awk 'BEGIN{x=8;x*=2;print x}'
  881  awk '/bash$/{x++} END{print x}' /etc/passwd
  882  who
  883  who | awk '$1=="root"{x++} END{print x}]
  884  '
  885  who | awk '$1=="root"{x++} END{print x}'
  886  seq 200 |awk '$1%7==0 && $1~/7/'
  887  df
  888  df |tail -n +2
  889  df |tail -n +2 |awk 'sum+=$4 END {print sum}'
  890  df |tail -n +2 |awk '{sum+=$4} END {print sum}'
  891  ls -l /etc/*.conf
  892  ls -l /etc/*.conf|awk '{sum+=$5} END{print sum}'
  893  ls -l /etc
  894  ls -l /etc |awk '/^~/{sum+=$5} END{print sum}'
  895  ls -l /etc |awk '/^-/{sum+=$5} END{print sum}'
  896  ps -eo user,pid,pcpu,comm
  897  ps -eo user,pid,pcpu,comm|awk '{ if ($3>0.5) {print} }'
  898  cd /etc/sysconfig/network-scripts/
  899  vim ifcfg-enp0s3 
  900  reboot
  901  ps -eo user,pid,pcpu,comm
  902  ps -eo user,pid,pcpu,comm|awk '{ if($3>0.5) {print} }'
  903  ps -eo user,pid,pcpu,comm|awk '{ if($3>0.0) {print} }'
  904  ps -eo user,pid,rsss,comm|awk '{ if($3>16) {print} }'
  905  ps -eo user,pid,rss,comm|awk '{ if($3>16) {print} }'
  906  ps -eo user,pid,rss,comm|awk '{ if($3>1024) {print} }'
  907  useradd rick
  908  useradd vicky
  909  awk -F: '{if($3<1000){x++}else{y++}} \
  910  END{print x, y}' /etc/passwd
  911  awk -F: '{if($3<1000){x++}else{y++}} \
  912  END{print x, y}' /etc/passwd
  913  ls -l /etc | awk '{
  914  if ($1~/^-/) {x++} else {y++} \
  915  }
  916  END {print x, y}'
  917  seq 10 |awk '{
  918  if ($1%2==0) {print $1"is odd";x++} else {print $1"is even";y++}
  919  }
  920  END {print x,y}
  921  '
  922  seq 10 |awk '{
  923  if ($1%2==0) {print $1"is odd";x++} else {print $1"is even";y++}
  924  }
  925  END {print x,y}
  926  '
  927  awk 'BEGIN{a[0]=11;print a[0]}''
  928  awk 'BEGIN{a[0]=11;print a[0]}'
  929  awk 'BEGIN{a[0]=11;print a["0"]}'
  930  awk 'BEGIN{ \
  931  tome["age"]=22; \
  932  tome["addr"]="beijing";
  933  print tome["age"], tome["addr"] \
  934  }'
  935  awk 'BEGIN{ \
  936  a[10]=11;a[88]=22;a["book"]=33;a["work"]="home";\
  937  for (i in a) {print i}
  938  }'
  939  df 
  940  df |awk 'NR!=1 {disk[$1]=$4} \
  941  END {for (i in disk) {printf i, disk[i]}
  942  }'
  943  df |awk 'NR!=1 {disk[$1]=$4} \
  944  END {for (i in disk) {printf disk[i]}
  945  }'
  946  df |awk 'NR!=1 {disk[$1]=$4} \
  947  END {for (i in disk) {printf "-20s %-10s\n", i, disk[i]}
  948  }'
  949  df |awk 'NR!=1 {disk[$1]=$4} \
  950  END {for (i in disk) {printf "%-20s %-10s\n", i, disk[i]}
  951  }'
  952  awk 'BEGIN{ for (i=1;i<=5;i++) {print i}}'
  953  awk '{for (i=1;i<=NF;i++) {if ($i=="is") x++ }} END {print x}' test.txt
  954  ll
  955  awk '{for (i=1;i<=NF;i++) {if ($i=="is") x++ }} END {print x}' ver2.txt
  956  awk 'BEGIN{ i=1;while(i<=5) {print i;i++} }'
  957  cd shell_demo/
  958  vim test.txt 
  959  awk '{i=1;while(i<=NR) {printf "%-2d", $i; i++} ; print " "}' test.txt 
  960  awk 'BEGIN {
  961  i=0;
  962  while(i<=5) {
  963    i++;
  964    if (i==3) {continue};
  965    print i
  966    };
  967  print "over"
  968  END {print "end"} ' /etc/hosts
  969  awk 'BEGIN {
  970  i=0;
  971  while(i<=5) {
  972    i++;
  973    if (i==3) {continue};
  974    print i
  975    };
  976  print "over" }
  977  END {print "end"} ' /etc/hosts
  978  awk 'BEGIN {
  979  i=0;
  980  while(i<=5) {
  981    i++;
  982    if (i==3) {break};
  983    print i
  984    };
  985  print "over" }
  986  END {print "end"} ' /etc/hosts
  987  awk 'BEGIN {
  988  i=0;
  989  while(i<=5) {
  990    i++;
  991    if (i==3) {exit};
  992    print i
  993    };
  994  print "over" }
  995  END {print "end"} ' /etc/hosts
  996  df -h
  997  df -h|awk '{print $4}'
  998  df -h |awk '{if(NF==1){getline; print$3};if(NF==6) {print$4}}'
  999  cd shell_demo/
 1000  history 
 1001  vim test.txt
 1002  awk '/air/{getline;print "netx line:",$0} print "normal line"}' test.txt 
 1003  awk '/air/{getline;print; "netx line:",$0} print "normal line"}' test.txt 
 1004  awk '/air/{getline;print; "netx line:",$0} {print "normal line"}' test.txt 
 1005  awk '/air/{getline;print "netx line:",$0} {print "normal line"}' test.txt 
 1006  awk '/air/{next;print "netx line:",$0} {print "normal line"}' test.txt 
 1007  awk 'BEGIN{system("ls")}'
 1008  awk 'BEGIN{system("echo test")}'
 1009  awk 'BEGIN{system("uptime")}'
 1010  awk '{system("echo date:"$0)}' test.txt
 1011  awk 'BEGIN{print cos(50)}'
 1012  awk 'BEGIN{print sin(45)}'
 1013  awk 'BEGIN{print sqrt(45)}'
 1014  awk 'BEGIN{print int(4.5)}'
 1015  awk 'BEGIN{print rand()}'
 1016  awk 'BEGIN{srand(); print rand()}'
 1017  awk 'BEGIN{test="hello the world"; print length(test)}'
 1018  cat /etc/shells 
 1019  awk '{print length()}' /etc/shells 
 1020  awk 'BEGIN{test="hello the world";print index(test,"h")};
 1021  awk 'BEGIN{test="hello the world";print index(test,"h")}'
 1022  awk 'BEGIN{test="hello the world";print index(test,"t")}'
 1023  awk 'BEGIN{print match("How much? 981$", "[0-9]")}'
 1024  awk 'BEGIN{print match("How much? 981$", "[a-z]")}'
 1025  awk 'BEGIN{print tolower("THIS IS A TEst")}'
 1026  awk 'BEGIN{apple="red aPPle";print toupper(apple[0])}'
 1027  awk 'BEGIN{apple="red aPPle";print toupper(apple)}'
 1028  awk 'BEGIN{split("hello the world", test);print test[3]}'
 1029  awk 'BEGIN{split("hello:the:world",test);print test[3]}'
 1030  awk 'BEGIN{split("hello:the:world",test);print test[1]}'
 1031  awk 'BEGIN{split("hello:the:world",test,":");print test[1]}'
 1032  awk 'BEGIN{hi="hello world";gsub("o","O",hi; print hi}'
 1033  awk 'BEGIN{hi="hello world";gsub("o","O",hi); print hi}'
 1034  head -l /etc/passwd
 1035  head -1 /etc/passwd
 1036  head -1 /etc/passwd |awk '{gsub("[0-9]","**");print $0}'
 1037  head -1 /etc/passwd |awk '{sub("[0-9]","**");print $0}'
 1038  awk 'BEGIN{hi="Hello World"; print substr(hi, 2, 3)}'
 1039  awk 'BEGIN{print systime()}'
 1040  awk '
function max(x,y) {
if (x>y) {print x}
else {print y}}
BEGIN{max(18,9)}'