How to Use 'History-C' Command in a Bash Script

How can I programmatically access the bash command history in C?

The closest you can get is

alias cmd="history | cmd"

and read standard input from the application.

History command works in a terminal, but doesn't when written as a bash script

Looking at your history only makes sense in an interactive shell. Make that command a function instead of a standalone script. In your ~/.bashrc, put

popular_history() {
    history | sort -k2 | uniq -c --skip-fields=1 | sort -r -g | head
}

Does bash shell script leave its command history?

No, it does not:
https://www.gnu.org/software/bash/manual/html_node/Bash-History-Facilities.html

9.1 Bash History Facilities

When the -o history option to the set builtin is enabled (see The Set Builtin), the shell provides access to the command history, the list of commands previously typed.

To get current settings, use set -o command. In interactive shells (with -i option of bash or in usual bashes from login or terminal) it prints history on. When used in scripts (bash -c 'set -o' or when you did ssh machine bash without tty allocation) it is unset: history off.

https://www.gnu.org/software/bash/manual/html_node/Interactive-Shell-Behavior.html

6.3.3 Interactive Shell Behavior - When the shell is running interactively, it changes its behavior in several ways.

7. Command history (see Bash History Facilities) and history expansion (see History Interaction) are enabled by default. Bash will save the command history to the file named by $HISTFILE when a shell with history enabled exits.

History can be enabled in script with several commands: https://askubuntu.com/questions/546556/how-can-i-use-history-command-in-a-bash-script / https://unix.stackexchange.com/questions/5684/history-command-inside-bash-script - set HISTFILE and (optionally) HISTTIMEFORMAT, enable with set -o history and then use history command.

How to add a command to the bash history from python

There is no cross-shell, universally portable option: History is an interactive facility without a close POSIX specification as to how it's implemented.

That said, there are some fixes needed to make the general approach attempted above both functional and safe:

subprocess.Popen(['bash', '-ic', 'set -o history; history -s "$1"', '_', command_string])

• The HISTFILE variable is only set in interactive shells. Thus, you need to run bash with -i to have it set at all.
• set -o history is similarly needed to turn history on.
• Passing command_string out-of-band instead of substituting it into the argument following -c avoids massive security bugs (where trying to append a line to history could execute parts of it instead).

Creating a history command for a shell program using the c language

One fix would be changing

char **cmdsHistory;

to

char *cmdsHistory[10]; //or any desire number/macro

But still your program leaks memory, by calling strdup and resetting i as 0 after a cycle. Please fix it though.

Fix for leak would be like

if (cmdsHistory[cmdHisC]) {
    free(cmdsHistory[cmdHisC]);
    cmdsHistory[cmdHisC] = cmdHistory;
}

Make sure you initialize all pointers to NULL on start up.

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