Perl write output file

Viewed 10k times. This is my code to telnet to the switches:! Improve this question. Danny Luk Danny Luk 47 1 1 gold badge 2 2 silver badges 10 10 bronze badges. Please turn on use strict; - it's as important as use warnings;.

Add a comment. Active Oldest Votes. Please Try the following! Improve this answer. Manu Mathew Manu Mathew 6 6 silver badges 17 17 bronze badges.

Thats great!! Thank you for your help. Whats wrong? Find centralized, trusted content and collaborate around the technologies you use most. Connect and share knowledge within a single location that is structured and easy to search. Same as MVS's answer , but modern and safe.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Best way to capture output from system command to a text file? Ask Question. Asked 10 years, 3 months ago. Active 6 years, 1 month ago. Viewed 40k times. Improve this question. Peter Mortensen Perl file test - How to determine whether you can read a file. Perl file write test - How to determine if you can write to a file.

Perl: How to extract lines from the middle of a text file. Scala 3 opaque types: How to create meaningful type names. Here's a program that reads a file and prints it in sorted order:. Perl is exceptionally good at file conversion. For simplicity, assume names have no spaces no Mary Anns, no Van Gelders. Here's a 21 line program to do the conversion:. Copyright C by Steve Litt -- Legal. File Slurping You might occasionally want to grab an entire file without paying attention to line termination.

This is called "slurping" the file. The following code slurps the STDIN file, then splits it into lines, then reassembles the lines into a single string, and prints the string: x! Now we undef the line terminator character Now we slurp the entirety of STDIN Now we restore the line terminator character Now we split the string we read using the termator as a border Now we join the array back into a string We print the string Last but not least, we print an extra newline to fix a picket fence condition Slurping isn't as handy as it might seem.

Not in Perl! For whatever reason, line oriented is faster. One reason is the need for huge amounts of memory, which on UNIX systems translates into huge disk usage as swap file space is used. But this doesn't account for the whole thing, as you'll see in the test following program:!

A line at a time input that pushed on an array and then outputted it a line at a time took 74 seconds. Note that this stores the full file in memory. The slurp method, which reads the file into a string and then copies it to an array, takes seconds.