Visit The New, Modern Unix Linux Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #865
Difficulty: Easy
The original idea of a member badging system at was first proposed by Ravinder Singh in 2018.
True or False?
Linux & Unix Commands - Search Man Pages

strdup(3) [freebsd man page]

STRDUP(3)						   BSD Library Functions Manual 						 STRDUP(3)

strdup, strndup -- save a copy of a string LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <string.h> char * strdup(const char *str); char * strndup(const char *str, size_t len); DESCRIPTION
The strdup() function allocates sufficient memory for a copy of the string str, does the copy, and returns a pointer to it. The pointer may subsequently be used as an argument to the function free(3). If insufficient memory is available, NULL is returned and errno is set to ENOMEM. The strndup() function copies at most len characters from the string str always NUL terminating the copied string. SEE ALSO
free(3), malloc(3), wcsdup(3) HISTORY
The strdup() function first appeared in 4.4BSD. The strndup() function was added in FreeBSD 7.2. BSD
December 5, 2008 BSD

Check Out this Related Man Page

STRDUP(3)						     Linux Programmer's Manual							 STRDUP(3)

strdup, strndup, strdupa, strndupa - duplicate a string SYNOPSIS
#include <string.h> char *strdup(const char *s); #define _GNU_SOURCE #include <string.h> char *strndup(const char *s, size_t n); char *strdupa(const char *s); char *strndupa(const char *s, size_t n); DESCRIPTION
The strdup() function returns a pointer to a new string which is a duplicate of the string s. Memory for the new string is obtained with malloc(3), and can be freed with free(3). The strndup() function is similar, but only copies at most n characters. If s is longer than n, only n characters are copied, and a termi- nating NUL is added. strdupa and strndupa are similar, but use alloca(3) to allocate the buffer. They are only available when using the GNU GCC suite, and suf- fer from the same limitations described in alloca(3). RETURN VALUE
The strdup() function returns a pointer to the duplicated string, or NULL if insufficient memory was available. ERRORS
ENOMEM Insufficient memory available to allocate duplicate string. CONFORMING TO
SVID 3, BSD 4.3. strndup(), strdupa(), and strndupa() are GNU extensions. SEE ALSO
alloca(3), calloc(3), free(3), malloc(3), realloc(3) GNU
1993-04-12 STRDUP(3)

13 More Discussions You Might Find Interesting

1. Programming

C++: No output for Char* when on AIX. Worked on Linux

Hi All, I have a script (attached) that was working fine on Linux. I compiled it there using g++ CrncyFmt.cpp -o CrncyFmt.o When I ran it there using eg. CrncyFmt.o 2343.565 2 I get as expected: CharOut = " 2,343.57" Now we have moved to our test box which is AIX and I... (11 Replies)
Discussion started by: Leedor
11 Replies

2. Programming

Hashtable + shared memory

Hello everyone, How to connect hash table with shared memory?.I need to update and retrieve data from the shared memory through hash table. Thanks in advance (13 Replies)
Discussion started by: andrew.paul
13 Replies

3. Programming

Memory free() in C

Hi guys. I've a question, if we are using a syscall that receives a string allocated dynamicaly to a determined size, or NUL and it will allocate the apropriate size. We should free the memory or the OS will do it for us? If a function returns a pointer we should free that poiter when we are done... (7 Replies)
Discussion started by: pharaoh
7 Replies

4. Programming

./match_pattern.out: malloc(): memory corruption: 0x0000000013a11600 ***

Hi All, I have a simple code which does some computation by matching string patterns. In brief: 1. The code reads .dat and .txt files. 2. .dat files are huge text files and .txt files contain some important words. 3. I am just doing strstr to find the patterns. 4. The function returns the... (3 Replies)
Discussion started by: shoaibjameel123
3 Replies

5. Programming

How to store argv[x] in my program???

Hi friends, I have this problem that I am facing, I want to store an argument which is passed to main, and I want to store it as an array of characters. I can store number arguments with the help of x = atoi(argv). Now suppose I passed the argument Hello to main, how can I store it somewhere in my... (6 Replies)
Discussion started by: gabam
6 Replies

6. Programming

C; storing strings in an array

I am trying to get userinput from stdin and store the lines in an array. If i do this: using a char **list to store strings allocate memory to it #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv) { char *prog = argv; char **linelist; int... (5 Replies)
Discussion started by: tornow
5 Replies

7. Programming

Malloc problem with fread() to read file to structure in C

Hello, I am trying to read a text file into linked list, but always got the first and last records wrong. 1) The problem looks related to the initialization of the node temp with malloc(), but could not figure it out. No error/warning at compiling, though. 2) The output file is empty,... (10 Replies)
Discussion started by: yifangt
10 Replies

8. Programming

Segment fault for C++ program when return vector

I am trying to reverse complement DNA sequence (string) with a short c++ code using boost library. Code was compiled without any warning/error, but ran into Segmentation fault. My guess is the function to return a vector, but not sure. #include <iostream> #include <fstream> #include <string>... (14 Replies)
Discussion started by: yifangt
14 Replies

9. AIX

Compiling problem - AIX 7.2

Hi We meet errors while running configuration scripts to prepare compiling source code on AIX 7.2. This error does not happen on AIX5.3 and AIX6.1 With the “/usr/bin/sh” from AIX7.2, sometimes , the script runs sucessfully, sometimes not. It’s unstable, and I don’t know why. When... (10 Replies)
Discussion started by: bobochacha29
10 Replies

10. UNIX for Beginners Questions & Answers

Adding to an array in an external file, and adding elements to it.

I have an array in an external file, "array.txt", which contains: char *testarray={"Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine"};I want to be able to add an element to this array, and have that element display, whenever I call it, without having to recompile... (29 Replies)
Discussion started by: ignatius
29 Replies

11. UNIX for Beginners Questions & Answers

Ncurses status bar

Hi, all, I'm writing a BBS telnet client, and am trying to implement a status bar into it, at the bottom of the screen. I am using NCurses to accomplish this. So far, it appears to be working, that is, upon connecting to BBS, it will display the status bar, and then quickly disappear. ... (5 Replies)
Discussion started by: ignatius
5 Replies

12. UNIX for Beginners Questions & Answers

NTP synchronised problem in our Centos 7.6 node

Someone, please help on this issue:- Note : for security reason i didn't mention hostnames and ips. ============================================================================== # ntpstat unsynchronised polling server every 1024 s Ntpstat showing unsynchronised. ... (29 Replies)
Discussion started by: shanmugaraj
29 Replies

13. UNIX for Beginners Questions & Answers

Displaying every other line in an array.

Hi, I have an array, that works well. But, I want to have it display every other line. Like so, 1, 3, 5, 7, etc, etc. Here is the relevant code: I'm sorry for the pastebin link. For some reason, I can't get the code to format properly with the code tags. code tags work fine... everyone... (4 Replies)
Discussion started by: ignatius
4 Replies

Featured Tech Videos