gnu

问题 The Beta release of gawk 4.2.0, available in http://www.skeeve.com/gawk/gawk-4.1.65.tar.gz is a major release, with many significant new features . I previously asked about What is the behaviour of FS = " " in GNU Awk 4.2?, and now I noticed the brand new typeof() function to deprecate isarray(): Changes from 4.1.4 to 4.2.0 The new typeof() function can be used to indicate if a variable or array element is an array, regexp, string or number. The isarray() function is deprecated in favor of

问题 I have the following Makefile SHELL=/bin/bash .SHELLFLAGS=-O extglob -o errexit -o pipefail -o nounset -c .PHONY: testing define getFileContents $(shell cat ./test.txt) endef TEST_STATIC=dummy deploy: $(eval TEST=$(getFileContents)) @echo "$(TEST)" ifeq ($(TEST),dummy) @echo "$(TEST) is FAILED" else @echo "$(TEST) is PASS" endif ifneq (,$(findstring dummy,$(TEST))) @echo "$(TEST) is FAILED" else @echo "$(TEST) is PASS" endif ifeq ($(TEST_STATIC),dummy) @echo "$(TEST) is FAILED" else @echo "$

问题 I am trying to run the following code, but I am getting the following error. error: cannot declare pointer to 'int&' #include <iostream> using namespace std; int main() { int x = 5; int *ptr = &x; int &(*y) = ptr; *y = 5; cout << *ptr << endl; return 0; } 回答1: If you just want a new pointer to the same region of memory, use: int *y = ptr; This not so much an "alias" in that if you change *ptr or *y , both will change, but if you change the pointers themselves, the other will not be updated.

问题 If if use, for example foo_SOURCES = bar.l then, automake generates via flex file bar.c . But, if I provide prefix AM_LFLAGS=-Psome_prefix , it generates lex.some_prefix.c , which is not known by other compilation rules, so it fails with bar.c: No such file or directory . Where is my mistake and how can I work around it? I really need prefix. 回答1: I think the only way around this is to write your own rule for the .l->.c translation. Something like: x_SOURCES = lex.some_prefix.c lex.some

问题 In my project makefile, there is a variable named "- -command-variables- -". I could guess its meaning from the context, but I want to know more about "- -command-variables- -". No result from google and GNU make manual. Here is my test makefile, all: $(warning $(-*-command-variables-*-)) #$(warning $(.VARIABLES)) #$(foreach v, $(.VARIABLES), $(info $v===>$($v))) When I type make test=Makefile , it prints out: Makefile:2: test=Makefile make: `all' is up to date. I found this variables is in

问题 GNU GCC Compiler Environment Variables Default-Search-Path — I am trying to change default values of GCC environment variables to new custom values so that the default search path will contain any needed additional libraries or include header files that I would like to use on a regular basis. My version of GNU GCC is: gcc (MinGW.org GCC Build-2) 9.2.0 Include directories for .h header files for this <…> not "…" which would be in the same directory as .c file extension. Include Header

问题 I'm looking through the glib header files that reside in /usr/include to get a feel for what is going on behind the scenes. All the files I'm looking at simply declare a bunch of macros and functions but I want to take a look at the implementation of these functions. 回答1: The glibc source repository is here: https://sourceware.org/git/?p=glibc.git;a=tree Note that a lot of the interesting code is under the sysdeps directory, particularly sysdeps/unix/sysv/linux/* . Also worth noting is that

问题 This could be an annoying question. But I was hoping someone could provide me with step by step instructions on how to get GLPK up and running on a Windows machine. I have Windows 7 64-bit. I have tried looking at some instructions on various websites but keep running into problems. I am not very versed in creating directories, working with binaries (e.g. what is a binary), etc.... Even running commands is a little foreign to me. To get an idea of what kind of detail I need in the

问题 I want to rename a lot of files (some jpg and a lot of png files) I need them sequentially numbered on each folder have this structure: .../folder01 file.png file.jpg .../folder02 file.png file.png .......... .../folder05 file.png file.png and I want something like this: .../folder01 0001.jpg 0002.png .../folder02 0003.png 0004.png .......... .../folder05 0012.png 0013.png how can I make it using bash? 回答1: Here's one way: find . \( -name '*.jpg' -o -name '*.png' \) -print | (i=0; while read

问题 I was learning about the makefile tool which seems very powerful, and was trying to figure out how to make it work since I have 4 different mains and a common class for 3 of them. What I'd like to get is: Linear: g++ -o linear linear.cpp Linear5: g++ -o linear5 linear5.cpp Contenidor.cpp Contenidor.h Logarithmic: g++ -o logarithmic logarithmic.cpp Contenidor.cpp Contenidor.h Constant: g++ -o constant constant.cpp Contenidor.cpp Contenidor.h With the following Makefile code: all: linear5