echo

问题 I know that this question is answered many times, but I still can't figure out how to do it. Maybe it's because I don't know the correct keyword to search for. Using echo -ne '\n' | enter doesn't work. My code is: #! /bin/bash #Grub-customizer sudo add-apt-repository ppa:danielrichter2007/grub-customizer echo -ne '\n' | return sudo apt-get update sudo apt-get install grub-customizer 回答1: You're supposed to pipe the \n into the command that's going to be receiving it (otherwise it won't ever

问题 How do I write non-ASCII characters using echo? Is there an escape sequence, such as \012 or something like that? I want to append ASCII characters to a file using: echo ?? >> file 回答1: Use echo -e "\012" 回答2: If you care about portability, you'll drop echo and use printf(1) : printf '\012' 回答3: On my terminal, printf '\012' >>output.txt works for both the octal representation of the ascii character, and the corresponding hexadecimal: printf '\xA' >>output.txt The command echo -en '\012' >

问题 How do I write non-ASCII characters using echo? Is there an escape sequence, such as \012 or something like that? I want to append ASCII characters to a file using: echo ?? >> file 回答1: Use echo -e "\012" 回答2: If you care about portability, you'll drop echo and use printf(1) : printf '\012' 回答3: On my terminal, printf '\012' >>output.txt works for both the octal representation of the ascii character, and the corresponding hexadecimal: printf '\xA' >>output.txt The command echo -en '\012' >

问题 How do I write non-ASCII characters using echo? Is there an escape sequence, such as \012 or something like that? I want to append ASCII characters to a file using: echo ?? >> file 回答1: Use echo -e "\012" 回答2: If you care about portability, you'll drop echo and use printf(1) : printf '\012' 回答3: On my terminal, printf '\012' >>output.txt works for both the octal representation of the ascii character, and the corresponding hexadecimal: printf '\xA' >>output.txt The command echo -en '\012' >

问题 i am trying to apply the background color in echo using an inline style but it is not applying background color in however changes only the text color. i want to change background color in a particular part of the code echo "<p style='color:orange';background-color:red;>"."record number: ".$rec_num. "</p>"."<br>" program code is class db_access { private $_uname; private $_pass; private $_db; private $_server; //_construct connects databaseand fetchest he result public function __construct(

问题 Suppose I'm reading a string using fgets, and I want to prevent that string's characters from echoing in the terminal internally (no bash tricks). How can I do that? 回答1: Assuming you're running on a POSIX-compatible OS, you need to play with local control terminal (termios) flags for stdin using tcgetattr() and tcsetattr(): #include <stdio.h> #include <termios.h> int main(int argc, char *argv[]) { printf("Enter password: "); struct termios term; tcgetattr(fileno(stdin), &term); term.c_lflag

问题 Suppose I'm reading a string using fgets, and I want to prevent that string's characters from echoing in the terminal internally (no bash tricks). How can I do that? 回答1: Assuming you're running on a POSIX-compatible OS, you need to play with local control terminal (termios) flags for stdin using tcgetattr() and tcsetattr(): #include <stdio.h> #include <termios.h> int main(int argc, char *argv[]) { printf("Enter password: "); struct termios term; tcgetattr(fileno(stdin), &term); term.c_lflag

问题 Suppose I'm reading a string using fgets, and I want to prevent that string's characters from echoing in the terminal internally (no bash tricks). How can I do that? 回答1: Assuming you're running on a POSIX-compatible OS, you need to play with local control terminal (termios) flags for stdin using tcgetattr() and tcsetattr(): #include <stdio.h> #include <termios.h> int main(int argc, char *argv[]) { printf("Enter password: "); struct termios term; tcgetattr(fileno(stdin), &term); term.c_lflag

问题 In bash, in this specific case, echo behaves like so: $ bash -c 'echo "a\nb"' a\nb but in zsh the same thing turns out very differently...: $ zsh -c 'echo "a\nb"' a b and fwiw in fish, because I was curious: $ fish -c 'echo "a\nb"' a\nb I did realize that I can run: $ zsh -c 'echo -E "a\nb"' a\nb But now I am worried that I'm about to stumble into more gotchas on such a basic operation. (Thus my investigation into fish: if I'm going to have to make changes at such a low level for zsh, why not

问题 In bash, in this specific case, echo behaves like so: $ bash -c 'echo "a\nb"' a\nb but in zsh the same thing turns out very differently...: $ zsh -c 'echo "a\nb"' a b and fwiw in fish, because I was curious: $ fish -c 'echo "a\nb"' a\nb I did realize that I can run: $ zsh -c 'echo -E "a\nb"' a\nb But now I am worried that I'm about to stumble into more gotchas on such a basic operation. (Thus my investigation into fish: if I'm going to have to make changes at such a low level for zsh, why not