1ABS(3) Linux Programmer's Manual ABS(3)
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6 abs, labs, llabs, imaxabs - compute the absolute value of an integer
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9 #include <stdlib.h>
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11 int abs(int j);
12 long int labs(long int j);
13 long long int llabs(long long int j);
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15 #include <inttypes.h>
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17 intmax_t imaxabs(intmax_t j);
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20 The abs() function computes the absolute value of the integer argument
21 j. The labs(), llabs() and imaxabs() functions compute the absolute
22 value of the argument j of the appropriate integer type for the func‐
23 tion.
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26 Returns the absolute value of the integer argument, of the appropriate
27 integer type for the function.
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30 SVr4, POSIX.1-2001, 4.3BSD, C99. C89 only includes the abs() and
31 labs() functions; the functions llabs() and imaxabs() were added in
32 C99.
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35 Trying to take the absolute value of the most negative integer is not
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38 The llabs() function is included in glibc since version 2.0, but is not
39 in libc5 or libc4. The imaxabs() function is included in glibc since
40 version 2.1.1.
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42 For llabs() to be declared, it may be necessary to define
43 _ISOC99_SOURCE or _ISOC9X_SOURCE (depending on the version of glibc)
44 before including any standard headers.
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46 GCC handles abs() and labs() as builtin functions. GCC 3.0 also han‐
47 dles llabs() and imaxabs() as builtins.
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50 cabs(3), ceil(3), fabs(3), floor(3), rint(3)
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54GNU 2000-12-17 ABS(3)