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Diffstat (limited to 'man2/brk.2')
| -rw-r--r-- | man2/brk.2 | 153 |
1 files changed, 0 insertions, 153 deletions
diff --git a/man2/brk.2 b/man2/brk.2 deleted file mode 100644 index 0248459..0000000 --- a/man2/brk.2 +++ /dev/null @@ -1,153 +0,0 @@ -.\" Copyright (c) 1993 Michael Haardt, (michael@moria.de) -.\" and Copyright 2006, 2008, Michael Kerrisk <tmk.manpages@gmail.com> -.\" Fri Apr 2 11:32:09 MET DST 1993 -.\" -.\" SPDX-License-Identifier: GPL-2.0-or-later -.\" -.\" Modified Wed Jul 21 19:52:58 1993 by Rik Faith <faith@cs.unc.edu> -.\" Modified Sun Aug 21 17:40:38 1994 by Rik Faith <faith@cs.unc.edu> -.\" -.TH brk 2 2023-10-31 "Linux man-pages 6.7" -.SH NAME -brk, sbrk \- change data segment size -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <unistd.h> -.P -.BI "int brk(void *" addr ); -.BI "void *sbrk(intptr_t " increment ); -.fi -.P -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.P -.BR brk (), -.BR sbrk (): -.nf - Since glibc 2.19: - _DEFAULT_SOURCE - || ((_XOPEN_SOURCE >= 500) && - ! (_POSIX_C_SOURCE >= 200112L)) -.\" (_XOPEN_SOURCE >= 500 || -.\" _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) && - From glibc 2.12 to glibc 2.19: - _BSD_SOURCE || _SVID_SOURCE - || ((_XOPEN_SOURCE >= 500) && - ! (_POSIX_C_SOURCE >= 200112L)) -.\" (_XOPEN_SOURCE >= 500 || -.\" _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) && - Before glibc 2.12: - _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 -.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED -.fi -.SH DESCRIPTION -.BR brk () -and -.BR sbrk () -change the location of the -.IR "program break" , -which defines the end of the process's data segment -(i.e., the program break is the first location after the end of the -uninitialized data segment). -Increasing the program break has the effect of -allocating memory to the process; -decreasing the break deallocates memory. -.P -.BR brk () -sets the end of the data segment to the value specified by -.IR addr , -when that value is reasonable, the system has enough memory, -and the process does not exceed its maximum data size (see -.BR setrlimit (2)). -.P -.BR sbrk () -increments the program's data space by -.I increment -bytes. -Calling -.BR sbrk () -with an -.I increment -of 0 can be used to find the current location of the program break. -.SH RETURN VALUE -On success, -.BR brk () -returns zero. -On error, \-1 is returned, and -.I errno -is set to -.BR ENOMEM . -.P -On success, -.BR sbrk () -returns the previous program break. -(If the break was increased, -then this value is a pointer to the start of the newly allocated memory). -On error, -.I "(void\ *)\ \-1" -is returned, and -.I errno -is set to -.BR ENOMEM . -.SH STANDARDS -None. -.SH HISTORY -4.3BSD; SUSv1, marked LEGACY in SUSv2, removed in POSIX.1-2001. -.\" -.\" .BR brk () -.\" and -.\" .BR sbrk () -.\" are not defined in the C Standard and are deliberately excluded from the -.\" POSIX.1-1990 standard (see paragraphs B.1.1.1.3 and B.8.3.3). -.SH NOTES -Avoid using -.BR brk () -and -.BR sbrk (): -the -.BR malloc (3) -memory allocation package is the -portable and comfortable way of allocating memory. -.P -Various systems use various types for the argument of -.BR sbrk (). -Common are \fIint\fP, \fIssize_t\fP, \fIptrdiff_t\fP, \fIintptr_t\fP. -.\" One sees -.\" \fIint\fP (e.g., XPGv4, DU 4.0, HP-UX 11, FreeBSD 4.0, OpenBSD 3.2), -.\" \fIssize_t\fP (OSF1 2.0, Irix 5.3, 6.5), -.\" \fIptrdiff_t\fP (libc4, libc5, ulibc, glibc 2.0, 2.1), -.\" \fIintptr_t\fP (e.g., XPGv5, AIX, SunOS 5.8, 5.9, FreeBSD 4.7, NetBSD 1.6, -.\" Tru64 5.1, glibc2.2). -.SS C library/kernel differences -The return value described above for -.BR brk () -is the behavior provided by the glibc wrapper function for the Linux -.BR brk () -system call. -(On most other implementations, the return value from -.BR brk () -is the same; this return value was also specified in SUSv2.) -However, -the actual Linux system call returns the new program break on success. -On failure, the system call returns the current break. -The glibc wrapper function does some work -(i.e., checks whether the new break is less than -.IR addr ) -to provide the 0 and \-1 return values described above. -.P -On Linux, -.BR sbrk () -is implemented as a library function that uses the -.BR brk () -system call, and does some internal bookkeeping so that it can -return the old break value. -.SH SEE ALSO -.BR execve (2), -.BR getrlimit (2), -.BR end (3), -.BR malloc (3) |