These commands are available on POSIX-compliant systems, as well as on traditional Unix based systems. If you are using some other operating system, you still need to be familiar with the ideas of I/O redirection and pipes.
Often, these systems use @command{gawk
All such differences appear in the index under the heading "differences between @command{gawk
GNU stands for "GNU's not Unix."
The terminology "GNU/Linux" is explained in the section Glossary.
Although we generally recommend the use of single quotes around the program text, double quotes are needed here in order to put the single quote into the message.
The `#!' mechanism works on Linux systems, systems derived from the 4.4-Lite Berkeley Software Distribution, and most commercial Unix systems.
The line beginning with `#!' lists the full file name of an interpreter to run and an optional initial command-line argument to pass to that interpreter. The operating system then runs the interpreter with the given argument and the full argument list of the executed program. The first argument in the list is the full file name of the @command{awk
In the C shell (@command{csh
On some very old systems, you may need to use `ls -lg' to get this output.
The `?' and `:' referred to here is the three-operand conditional expression described in section Conditional Expressions. Splitting lines after `?' and `:' is a minor @command{gawk
In other literature, you may see a character list referred to as either a character set, a character class or a bracket expression.
Use two backslashes if you're using a string constant with a regexp operator or function.
Experienced C and C++ programmers will note that it is possible, using something like `IGNORECASE = 1 && /foObAr/ { ... }' and `IGNORECASE = 0 || /foobar/ { ... }'. However, this is somewhat obscure and we don't recommend it.
At least that we know about.
In POSIX @command{awk
The @command{sed
Older versions of @command{gawk
The technical terminology is rather morbid. The finished child is called a "zombie," and cleaning up after it is referred to as "reaping."
The internal representation of all numbers, including integers, uses double-precision floating-point numbers. On most modern systems, these are in IEEE 754 standard format.
Pathological cases can require up to 752 digits (!), but we doubt that you need to worry about this.
The POSIX standard is under revision. The revised standard's rules for typing and comparison are the same as just described for @command{gawk
The original version of @command{awk
In POSIX @command{awk
Some early implementations of Unix @command{awk
Thanks to Michael Brennan for pointing this out.
The C version of rand
is known to produce fairly poor sequences of random numbers.
However, nothing requires that an @command{awk
Computer generated random numbers really are not truly random. They are technically known as "pseudo-random." This means that while the numbers in a sequence appear to be random, you can in fact generate the same sequence of random numbers over and over again.
Unless you use the @option{--non-decimal-data
This is different from C and C++, where the first character is number zero.
This consequence was certainly unintended.
As this Info file was being finalized, we learned that the POSIX standard will not use these rules. However, it was too late to change @command{gawk
A program is interactive if the standard output is connected to a terminal device.
See section Glossary, especially the entries for "Epoch" and "UTC."
The GNU @command{date
Occasionally there are minutes in a year with a leap second, which is why the seconds can go up to 60.
As this
is a recent standard, not every system's strftime necessarily
supports all of the conversions listed here.
If you don't understand any of this, don't worry about it; these facilities are meant to make it easier to "internationalize" programs. Other internationalization features are described in @ref{Internationalization, ,Internationalization with @command{gawk
This is because ISO C leaves the
behavior of the C version of strftime undefined and @command{gawk
This example shows that 0's come in on the left side. For @command{gawk
For some operating systems, the @command{gawk
Americans
use a comma every three decimal places and a period for the decimal
point, while many Europeans do exactly the opposite:
1,234.56 vs. 1.234,56.
Eventually, the @command{xgettext
This example is borrowed
from the GNU gettext manual.
This is good fodder for an "Obfuscated @command{awk
Perhaps it would be better if it were called "Hippy." Ah, well.
This is very different from the same operator in the C shell, @command{csh
Not recommended.
Your version of @command{gawk
The effects are
not identical. Output of the transformed
record will be in all lowercase, while IGNORECASE preserves the original
contents of the input record.
While all the library routines could have been rewritten to use this convention, this was not done, in order to show how my own @command{awk
@command{gawk
http://mathworld.wolfram.com/CliffRandomNumberGenerator.hmtl
ASCII
has been extended in many countries to use the values from 128 to 255
for country-specific characters. If your system uses these extensions,
you can simplify _ord_init to simply loop from 0 to 255.
It would be nice if @command{awk
This function was written before @command{gawk
It is often the case that password information is stored in a network database.
It also introduces a subtle bug; if a match happens, we output the translated line, not the original.
@command{wc
On some older System V systems, @command{tr
This program was written before @command{gawk
"Real world" is defined as "a program actually used to get something done."
On some very old versions of @command{awk
http://cm.bell-labs.com/who/bwk
This version is edited slightly for presentation. The complete version can be found in `extension/filefuncs.c' in the @command{gawk
Compiled programs are typically written in lower-level languages such as C, C++, Fortran, or Ada, and then translated, or compiled, into a form that the computer can execute directly.
http://www.validgh.com/goldberg/paper.ps
Pathological cases can require up to 752 digits (!), but we doubt that you need to worry about this.
This document was generated on 23 October 2001 using the texi2html translator version 1.54.