Greetings. I want to make it possible to edit a variable, but I did not find a function to add the text of an already existing value to the input line of the console, to edit it. Do not tell me the function?

PS The question is stupid, but Google does not give anything because of the dominance of other stupid questions.

  • Do you want to do this in the console? - yrHeTaTeJlb
  • @yrHeTaTeJlb yes - Happy_Cougar
  • one
    Look at The GNU Readline Library and at the same time the GNU History Library , with which you can "flipping" the previously entered data (as bash does on the command line) - avp
  • If for linux, you can adapt a simple line editor from another question. Stackoverflow.com/a/561208/130 - sercxjo

2 answers 2

Here is a (rather artificial) example of using GNU readline in C (also compiles g ++)
(and here is the link to it for windows )

The program analyzes the read line and if it contains a word beginning with V: then it is substituted for the input of the next line.

 #include <stdio.h> #include <stdlib.h> #include <readline/readline.h> #include <readline/history.h> static char *ins; int f() { if (ins && ins[0]) { rl_insert_text(ins); rl_redisplay(); } } int main (int ac, char *av[]) { char *line = 0, txt[1000] = "", *p; rl_pre_input_hook = f; // readline() вызовет нашу функцию перед чтением ввода (после вывода промпта) rl_bind_key('\t', rl_insert); // для вставки символа табуляции (иначе он работает как поиск дополнения имени файла) ins = txt; while (line = readline("> ")) { printf("line: %s\n", *line ? line : ""); txt[0] = 0; if (p = strstr(line, "V:")) sscanf(p, "%s", txt); if (line[0]) add_history(line); free(line); } return puts("End") == EOF; }

Since nested functions are not supported in C ++, the f() function (readline hook) and the char txt[] array (or a pointer to it, as in this example) have to be moved to an external level.

Call example:

 avp@avp-ubu1:hashcode$ g++ t-readline.c -lreadline avp@avp-ubu1:hashcode$ ./a.out > ksdkk line: ksdkk > ueru V:444 line: ueru V:444 > V:444 kksk line: V:444 kksk > End

In line 5 (the third call to readline), the text V:444 at the beginning of the input area is substituted from the previously entered line.

    Since the system is not specified, I answer for Linux. The ioctl system call with the request TIOCSTI number places one byte into the input queue of the terminal or serial port. Example of use:

     #include <sys/ioctl.h> ... for(const char*s="моя строка"; *s; s++) ioctl(0, TIOCSTI, s);

    A source

    In Windows, you can use the WriteConsoleInput function to simulate keyboard input .