Awk/scripts - Revision history

Christoph: /* Passing in Bash / environment variables */

2021-10-26T22:57:34Z

‎Passing in Bash / environment variables

2018-09-13T20:20:16Z

‎Christoph's additions

2018-09-13T18:58:49Z

‎Unix sockets

2017-08-16T23:12:17Z

‎Other examples

2016-02-23T21:41:20Z

‎Unix sockets

2016-02-10T23:38:29Z

‎Pattern ranges

2015-10-11T06:23:19Z

‎Unix sockets

2015-10-11T02:12:56Z

‎Christoph's additions

2015-07-28T21:58:31Z

‎Christoph's additions

2014-11-03T11:29:36Z

‎Date formats

@@ Line 423: / Line 423: @@
     h[i]=strtonum("0x" h[i]);};
     printf("%d.%d.%d.%d:%d\n",h[4],h[3],h[2],h[1],strtonum("0x" a[2]));}' /proc/net/udp
 ===Passing in Bash / environment variables===

@@ Line 423: / Line 423: @@
     h[i]=strtonum("0x" h[i]);};
     printf("%d.%d.%d.%d:%d\n",h[4],h[3],h[2],h[1],strtonum("0x" a[2]));}' /proc/net/udp
 ==References==

@@ Line 405: / Line 405: @@
   done
-Nice, but, let's do this in pure `awk`:
+Nice, but, let's do this in pure Awk:
   awk 'NR>1{split($2, addr, ":"); for(i=0;i<4;i++){
@@ Line 418: / Line 418: @@
                             rshift(and(ip,0xff000000),24))}'
-Final, pure `awk`:
+Final, pure Awk:
   awk 'NR>1{split($2, a, ":");patsplit(a[1],h,/.{2}/);for(i=4;i>0;i--){

@@ Line 197: / Line 197: @@
   BEGIN { FS="[^a-zA-Z]+"}
   { for (i=1; i<=NF; i++)
-      words[tolower($i)]++
+     words[tolower($i)]++
+  }
   END { for (i in words)
@@ Line 203: / Line 203: @@
+  }
 *Another way to calculate word frequencies (also uses associative arrays):
-  awk '   {for(i = 1; i <=NF; i++)
+  awk '{for(i = 1; i <=NF; i++)
-            num[$i]++
+         num[$i]++
+      }
       END {for(word in num)
-            print word, num[word]
+         print word, num[word]
+      }
       ' $*
@@ Line 263: / Line 263: @@
 *Print all lines between start/stop pairs:
-  awk '/start/, /stop/' file
+  awk '/start/,/stop/' file
 *Print all lines whose first field is different from previous one:
@@ Line 287: / Line 287: @@
 *Print "hi.0010" to "hi.0099":
-  yes | head -90 | awk '{printf("hi00%2.0f \n", NR+9)}'
+  yes | head -90 | awk '{printf("hi00%2.0f\n", NR+9)}'
 *Print out 4 random numbers between 0 and 1
   yes | head -4 | awk '{print rand()}'
 *Print out 40 random integers modulo 5
@@ Line 296: / Line 298: @@
 *Replace every field by its absolute value
-  { for (i = 1; i <= NF; i=i+1) if ($i < 0) $i = -$i print}
+  {for (i = 1; i <= NF; i=i+1) if ($i < 0) $i = -$i print}
 *If you have another character that delimits fields, use the -F option. For example, to print out the phone number for "Brown" in the following file,

← Older revision		Revision as of 21:41, 23 February 2016
Line 391:		Line 391:

	===Unix sockets===		===Unix sockets===
		+
		+	: see [[Unix sockets]] for more information.

	* Get a list of local IP addresses and ports listening via UDP:		* Get a list of local IP addresses and ports listening via UDP:

@@ Line 96: / Line 96: @@
 *Perform an action for lines 100 through 200:
   NR == 100, NR == 200 { ... }
 ===Built-in functions===

@@ Line 393: / Line 393: @@
   $ netstat -planu | awk '/^udp / {print $4}'
-Let's get the same info via the <code>/proc</code> filesystem:
+Let's get the same info via the <code>/proc</code> pseudo-filesystem:
   for h in $(awk 'NR>1{print $2}' /proc/net/udp); do

@@ Line 368: / Line 368: @@
   $ gawk '{print $2}' Ecoli.top.cai | sort > Ecoli.top.cai.col2
   $ comm -12 Ecoli.travers.col2 Ecoli.top.cai.col2 | wc -l
 === Date formats ===

@@ Line 384: / Line 384: @@
          print $0
        }' infile.csv
 ==References==

@@ Line 372: / Line 372: @@
 * Convert from "Jun 21 2011 5:00PM" to "2011-06-21":
   $ echo "Jun 21 2011 5:00PM" | awk '{"date \"+%F\" -d \""$1" "$2" "$3" \"" | getline var; print var}'
 ==References==