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Diffstat (limited to 'lib/libc/string/strverscmp.3')
| -rw-r--r-- | lib/libc/string/strverscmp.3 | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/lib/libc/string/strverscmp.3 b/lib/libc/string/strverscmp.3 new file mode 100644 index 000000000000..495e5c8780c1 --- /dev/null +++ b/lib/libc/string/strverscmp.3 @@ -0,0 +1,56 @@ +.\" SPDX-License-Identifier: BSD-2-Clause +.\" Copyright (c) 2022 Aymeric Wibo <obiwac@gmail.com> +.Dd August 31, 2023 +.Dt STRVERSCMP 3 +.Os +.Sh NAME +.Nm strverscmp +.Nd compare strings according to natural order +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In string.h +.Ft int +.Fn strverscmp "const char *s1" "const char *s2" +.Sh DESCRIPTION +The +.Fn strverscmp +function +compares the null-terminated strings +.Fa s1 +and +.Fa s2 +according to their natural order +and returns an integer greater than, equal to, or less than 0, +depending on whether +.Fa s1 +is greater than, equal to, or less than +.Fa s2 . +.Pp +More specifically, this natural order is found by iterating over both +strings until a difference is found. +If the difference is between non-decimal characters, +.Fn strverscmp +acts like +.Xr strcmp 3 +(thus, the ordering would be "a", "b", "train"). +If a decimal digit is found, the whole number is read and compared +(thus, the ordering would be "9", "10", "420" which is different to lexicographic order, +what +.Xr strcmp 3 +would have done). +Numbers with leading zeroes are interpreted as fractional parts (even without a decimal point), +and numbers with more leading zeroes are placed before numbers with fewer leading zeroes +(thus, the ordering would be "000", "00", "01", "010", "09", "0", "1", "9", "10"). +.Sh SEE ALSO +.Xr strcmp 3 , +.Xr versionsort 3 +.Sh STANDARDS +The +.Fn strverscmp +function is a GNU extension and conforms to no standard. +.Sh HISTORY +The +.Fn strverscmp +function was added in +.Fx 13.2 . |