## Linux and UNIX Man Pages

Test Your Knowledge in Computers #895
Difficulty: Medium
The GNU Core Utilities or coreutils is a package of GNU software containing reimplementations for many of the basic tools, such as cat, ls, and rm, which are used on Unix-like operating systems.
True or False?

# log(3) [freebsd man page]

```LOG(3)							   BSD Library Functions Manual 						    LOG(3)

NAME
log, logf, logl, log10, log10f, log10l, log2, log2f, log2l, log1p, log1pf, log1pl -- logarithm functions

LIBRARY
Math Library (libm, -lm)

SYNOPSIS
#include <math.h>

double
log(double x);

float
logf(float x);

long double
logl(long double x);

double
log10(double x);

float
log10f(float x);

long double
log10l(long double x);

double
log2(double x);

float
log2f(float x);

long double
log2l(long double x);

double
log1p(double x);

float
log1pf(float x);

long double
log1pl(long double x);

DESCRIPTION
The log(), logf(), and logl() functions compute the natural logarithm of x.

The log10(), log10f(), and log10l() functions compute the logarithm base 10 of x, while log2(), log2f(), and log2l() compute the logarithm
base 2 of x.

The log1p(), log1pf(), and log1pl() functions compute the natural logarithm of 1 + x.  Computing the natural logarithm as log1p(x) is more
accurate than computing it as log(1 + x) when x is close to zero.

RETURN VALUES
These functions return the requested logarithm; the logarithm of 1 is +0.	An attempt to take the logarithm of +-0 results in a divide-by-
zero exception, and -infinity is returned.  Otherwise, attempting to take the logarithm of a negative number results in an invalid exception
and a return value of NaN.

exp(3), ilogb(3), math(3), pow(3)

STANDARDS
The log(), logf(), logl(), log10(), log10f(), log10l(), log2(), log2f(), log2l(), log1p(), log1pf(), and log1pl() functions conform to
ISO/IEC 9899:1999 (``ISO C99'').

BSD								   June 3, 2013 							       BSD```

## Check Out this Related Man Page

```LOG(3)							   BSD Library Functions Manual 						    LOG(3)

NAME
log, logf, logl, log10, log10f, log10l, log2, log2f, log2l, log1p, log1pf, log1pl -- logarithm functions

LIBRARY
Math Library (libm, -lm)

SYNOPSIS
#include <math.h>

double
log(double x);

float
logf(float x);

long double
logl(long double x);

double
log10(double x);

float
log10f(float x);

long double
log10l(long double x);

double
log2(double x);

float
log2f(float x);

long double
log2l(long double x);

double
log1p(double x);

float
log1pf(float x);

long double
log1pl(long double x);

DESCRIPTION
The log(), logf(), and logl() functions compute the natural logarithm of x.

The log10(), log10f(), and log10l() functions compute the logarithm base 10 of x, while log2(), log2f(), and log2l() compute the logarithm
base 2 of x.

The log1p(), log1pf(), and log1pl() functions compute the natural logarithm of 1 + x.  Computing the natural logarithm as log1p(x) is more
accurate than computing it as log(1 + x) when x is close to zero.

RETURN VALUES
These functions return the requested logarithm; the logarithm of 1 is +0.	An attempt to take the logarithm of +-0 results in a divide-by-
zero exception, and -infinity is returned.  Otherwise, attempting to take the logarithm of a negative number results in an invalid exception
and a return value of NaN.

exp(3), ilogb(3), math(3), pow(3)

STANDARDS
The log(), logf(), logl(), log10(), log10f(), log10l(), log2(), log2f(), log2l(), log1p(), log1pf(), and log1pl() functions conform to
ISO/IEC 9899:1999 (``ISO C99'').

BSD								   June 3, 2013 							       BSD```

## logarithm

Hi Guys, Is it possible to do Logarithm of a number in Unix?? i dunno how to handl logarithm operation

## Binary logarithm

Hi all, I wonder how I can use binary logarithm in Solaris shell. I'm aware of the natural logarithm as discussed on the following post: https://www.unix.com/shell-programming-scripting/68175-logarithm.html Do you have any idea ? Thanks in advanced, Yigal

## deleting double entries in a log file

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## How to divide results into several pages?

Hi All, I am wondering if anyone can help me with this. I have a long list of results and I want to divide them into several pages. Any ideas of how to do this? I'm using perl languange. eg: Output file consist of 400 data then would like to divide it into 50 data per pages. any help on...

## Symbol referencing errors

Undefined first referenced symbol in file logf /var/tmp//ccwztFsO.o ld: fatal: Symbol referencing errors. No output written to a.out collect2: ld returned 1 exit status float exponC(float mean) { index1++;...

## Logrotate exclude log file

Hi all ! I've an issue to exclude a log file from logrotate, I tried this below: /var/log/apache2/*.log { olddir /var/log/apache2/old missingok rotate 50 compress copytruncate notifempty create 644 root root } I tried also:...