postgres/src/bin/psql/input.c

#include <config.h>
#include <c.h>
#include "input.h"

#include <pqexpbuffer.h>

/* Note that this file does not depend on any other files in psql. */

/* Runtime options for turning off readline and history */
/* (of course there is no runtime command for doing that :) */
#ifdef USE_READLINE
static bool useReadline;
#endif
#ifdef USE_HISTORY
static bool useHistory;
#endif


/*
 * gets_interactive()
 *
 * Gets a line of interactive input, using readline of desired.
 * The result is malloced.
 */
char *
gets_interactive(const char *prompt)
{
    char * s;

#ifdef USE_READLINE
    if (useReadline) {
	s = readline(prompt);
	fputc('\r', stdout);
	fflush(stdout);
    }
    else {
#endif
	fputs(prompt, stdout);
	fflush(stdout);
	s = gets_fromFile(stdin);
#ifdef USE_READLINE
    }
#endif

#ifdef USE_HISTORY
    if (useHistory && s && s[0] != '\0')
	add_history(s);
#endif

    return s;
}



/*
 * gets_fromFile
 *
 * Gets a line of noninteractive input from a file (which could be stdin).
 */
char *
gets_fromFile(FILE *source)
{
    PQExpBufferData buffer;
    char line[1024];

    initPQExpBuffer(&buffer);

    while (fgets(line, 1024, source) != NULL) {
	appendPQExpBufferStr(&buffer, line);
	if (buffer.data[buffer.len-1] == '\n') {
	    buffer.data[buffer.len-1] = '\0';
	    return buffer.data;
	}
    }

    if (buffer.len > 0)
	return buffer.data;		/* EOF after reading some bufferload(s) */

    /* EOF, so return null */
    termPQExpBuffer(&buffer);
    return NULL;
}



/*
 * Put any startup stuff related to input in here. It's good to maintain
 * abstraction this way.
 *
 * The only "flag" right now is 1 for use readline & history.
 */
void
initializeInput(int flags)
{
#ifdef USE_READLINE
    if (flags == 1) {
	useReadline = true;
	rl_readline_name = "psql";
    }
#endif

#ifdef USE_HISTORY
    if (flags == 1) {
	const char * home;

	useHistory = true;
	using_history();
	home = getenv("HOME");
	if (home) {
	    char * psql_history = (char *) malloc(strlen(home) + 20);
	    if (psql_history) {
		sprintf(psql_history, "%s/.psql_history", home);
		read_history(psql_history);
		free(psql_history);
	    }
	}
    }
#endif
}



bool
saveHistory(const char *fname)
{
#ifdef USE_HISTORY
    if (useHistory) {
	if (write_history(fname) != 0) {
	    perror(fname);
	    return false;
	}
	return true;
    }
    else
	return false;
#else
    return false;
#endif
}



void
finishInput(void)
{
#ifdef USE_HISTORY
    if (useHistory) {
	char * home;
	char * psql_history;

	home = getenv("HOME");
	if (home) {
	    psql_history = (char *) malloc(strlen(home) + 20);
	    if (psql_history) {
		sprintf(psql_history, "%s/.psql_history", home);
		write_history(psql_history);
		free(psql_history);
	    }
	}
    }
#endif
}