Perl - Revision history

Stuart: /* Using %ENV to pass in parameters */

2018-09-14T13:04:31Z

‎Using %ENV to pass in parameters

2018-07-18T16:34:26Z

‎Oneliners

2018-07-18T16:33:53Z

‎Using %ENV to pass in parameters

2018-07-11T12:39:24Z

‎Add a line after another one in a file using Perl

2018-07-11T12:38:42Z

‎Using %ENV to pass in parameters

2018-07-05T15:10:30Z

‎BEGIN and END

2018-07-05T15:09:56Z

‎perl -a

2017-09-15T14:52:41Z

‎What Perl modules are installed?

2017-07-10T10:54:33Z

‎Perl emulation of dos2unix command

2017-07-10T10:50:58Z

‎Perl emulation of dos2unix command

@@ Line 31: / Line 31: @@
-===Using %ENV to pass in parameters===
+===Using %ENV to pass parameters to a perl one-liner===
 Used here to clean up a comma-separated list of parameters passed into a shell.<br />
 <pre>

@@ Line 4: / Line 4: @@
 ==Oneliners==
 To change only the fifth line, you can add a test checking $., the input line number, then only perform the operation when the test passes:
 <pre>

@@ Line 5: / Line 5: @@
 ==Oneliners==
 Perl one-liners can be a great time/code saver. Here are a few I found useful.
 ===Using %ENV to pass in parameters===
 Used here to clean up a comma-separated list of parameters passed into a shell.<br />
@@ Line 14: / Line 41: @@
 SCHEMAE=`export quot="'"; echo $SCHEMAE | perl -lpe 's/\s+//g; s/$ENV{quot}//g; s/,/$ENV{quot},$ENV{quot}/g'`
 </pre>
 ===Add a line after another one in a file using Perl===
 Use Perl to filter a script (or a load of scripts) and add an extra line when certain pattern match condition exists.<br />

@@ Line 15: / Line 15: @@
 </pre>
 ===Add a line after another one in a file using Perl===
-Use Perl to filter a script (or a load of scripts) and add an extra line when certain pattern match condition exists. Uses -n switch with print because using -p switch evaluates your condition first and '''then''' prints the line.<br />
+Use Perl to filter a script (or a load of scripts) and add an extra line when certain pattern match condition exists.<br />
-This could be used if you want to print a line '''before''' the matched line!
+Uses -n switch with print because using -p switch evaluates your condition first and '''then''' prints the line. This could be used if you want to print a line '''before''' the matched line!
 <pre>
 for commvaulthost in ci00031669-hn491 ci00031670-hn492 ci00031671-hn5407 ci00031672-hn364 ci00031673-hn5207 ci00031674-hn5217; do

@@ Line 13: / Line 13: @@
 # -----------------------------
 SCHEMAE=`export quot="'"; echo $SCHEMAE | perl -lpe 's/\s+//g; s/$ENV{quot}//g; s/,/$ENV{quot},$ENV{quot}/g'`
 </pre>

@@ Line 30: / Line 30: @@
 Replace the 'n' with a 'p' to see the numbers being summed.
 <pre>
-perl -F, -anle '$sum += $F[1]; END { print $sum }' somefile.csv
+perl -F, -lane '$sum += $F[1]; END { print $sum }' somefile.csv
 </pre>

@@ Line 19: / Line 19: @@
 Breaks down the input into elements of an automatically assigned array called @F.
 <pre>
-perl -F: -anle 'print $F[0]' /etc/passwd
+perl -F: -lane 'print $F[0]' /etc/passwd
 </pre>

@@ Line 64: / Line 64: @@
      );
 print join "\n", @files;
 </pre>

@@ Line 93: / Line 93: @@
 ===Perl emulation of dos2unix command===
 <pre>
-perl -p -i -e 'tr/\r\n/\n/' filename
+perl -p -i -e 's/\r\n/\n/' filename
 </pre>
 and then back again with unix2dos
 <pre>
-perl -p -i -e 'tr/[!\r]\n/\r\n/' filename
+perl -p -i -e 's/[!\r]\n/\r\n/' filename
 </pre>