# gnuplot_i interface richtig verwenden



## Poolshark (23. April 2009)

hallo!

ich studiere astrononmie im 6.semester und muss nun für ein projekt ein nummerisches problem lösen. das programm selbst ist kein problem aber die graphikausgabe über ein interface stellt (für mich) ein großes problem dar. ich verwende jetzt das gnuplot_i.h bzw. gnuplot_i.c interface in der etwas unschönen methode durch direktes einbinden der beiden dateien durch #include gnuplot_i.c. mein quellcode zum testen sieht folgendermaßen aus:

```
#include <stdio.h>
#include <stdlib.h>
#include "gnuplot_i.h"
#include "gnuplot_i.c"


int main (void) {
	
	gnuplot_ctrl    *h ;
	
	h=gnuplot_init();
	gnuplot_cmd(h, "plot sin(x)");
	sleep(3);
	gnuplot_close(h);
	
}
```

wenn ich das nun im debugger laufen lasse kommt folgendes:

```
The Debugger Debugger is attaching to process
[Session started at 2009-04-23 11:18:45 +0200.]
cannot find gnuplot in your PATH
[Session started at 2009-04-23 11:18:45 +0200.]
Loading program into debugger…
GNU gdb 6.3.50-20050815 (Apple version gdb-962) (Sat Jul 26 08:14:40 UTC 2008)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-apple-darwin".Program loaded.
sharedlibrary apply-load-rules all
Attaching to program: `/test_gnu/build/Debug/test_gnu', process 3924.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
Program received signal:  “EXC_BAD_ACCESS”.
(gdb) continue
```
ich verwende xcode für mac os X. ein gnuplot paket ist installiert und funktioniert.
habe versucht herauszufinden warum das programm anfangs den pfad nicht erkennt, aber dazu reichen meine programmierkenntnisse einfach nicht aus...

der quellcode von gnuplot_i.c lautet folgender maßen:


```
/*-------------------------------------------------------------------------*/
/**
 @file		gnuplot_i.c
 @author	N. Devillard
 @date	Sep 1998
 @version	$Revision: 2.10 $
 @brief	C interface to gnuplot.
 
 gnuplot is a freely available, command-driven graphical display tool for
 Unix. It compiles and works quite well on a number of Unix flavours as
 well as other operating systems. The following module enables sending
 display requests to gnuplot through simple C calls.
 
 */
/*--------------------------------------------------------------------------*/

/*
 $Id: gnuplot_i.c,v 2.10 2003/01/27 08:58:04 ndevilla Exp $
 $Author: ndevilla $
 $Date: 2003/01/27 08:58:04 $
 $Revision: 2.10 $
 */

/*---------------------------------------------------------------------------
 Includes
 ---------------------------------------------------------------------------*/

#include "gnuplot_i.h"

/*---------------------------------------------------------------------------
 Defines
 ---------------------------------------------------------------------------*/

/** Maximal size of a gnuplot command */
#define GP_CMD_SIZE     	2048
/** Maximal size of a plot title */
#define GP_TITLE_SIZE   	80
/** Maximal size for an equation */
#define GP_EQ_SIZE      	512
/** Maximal size of a name in the PATH */
#define PATH_MAXNAMESZ       4096

/** Define P_tmpdir if not defined (this is normally a POSIX symbol) */
#ifndef P_tmpdir
#define P_tmpdir "."
#endif

/*---------------------------------------------------------------------------
 Function codes
 ---------------------------------------------------------------------------*/


/*-------------------------------------------------------------------------*/
/**
 @brief	Find out where a command lives in your PATH.
 @param	pname Name of the program to look for.
 @return	pointer to statically allocated character string.
 
 This is the C equivalent to the 'which' command in Unix. It parses
 out your PATH environment variable to find out where a command
 lives. The returned character string is statically allocated within
 this function, i.e. there is no need to free it. Beware that the
 contents of this string will change from one call to the next,
 though (as all static variables in a function).
 
 The input character string must be the name of a command without
 prefixing path of any kind, i.e. only the command name. The returned
 string is the path in which a command matching the same name was
 found.
 
 Examples (assuming there is a prog named 'hello' in the cwd):
 
 @verbatim
 gnuplot_get_program_path("hello") returns "."
 gnuplot_get_program_path("ls") returns "/bin"
 gnuplot_get_program_path("csh") returns "/usr/bin"
 gnuplot_get_program_path("/bin/ls") returns NULL
 @endverbatim
 
 */
/*-------------------------------------------------------------------------*/
char * gnuplot_get_program_path(char * pname)
{
    int         i, j, lg;
    char    *   path;
    static char buf[PATH_MAXNAMESZ];
	
    /* Trivial case: try in CWD */
    sprintf(buf, "./%s", pname) ;
    if (access(buf, X_OK)==0) {
        sprintf(buf, ".");
        return buf ;
    }
    /* Try out in all paths given in the PATH variable */
    buf[0] = 0;
    path = getenv("PATH") ;
    if (path!=NULL) {
        for (i=0; path[i]; ) {
            for (j=i ; (path[j]) && (path[j]!=':') ; j++);
            lg = j - i;
            strncpy(buf, path + i, lg);
            if (lg == 0) buf[lg++] = '.';
            buf[lg++] = '/';
            strcpy(buf + lg, pname);
            if (access(buf, X_OK) == 0) {
                /* Found it! */
                break ;
            }
            buf[0] = 0;
            i = j;
            if (path[i] == ':') i++ ;
        }
    } else {
		fprintf(stderr, "PATH variable not set\n");
	}
    /* If the buffer is still empty, the command was not found */
    if (buf[0] == 0) return NULL ;
    /* Otherwise truncate the command name to yield path only */
    lg = strlen(buf) - 1 ;
    while (buf[lg]!='/') {
        buf[lg]=0 ;
        lg -- ;
    }
    buf[lg] = 0;
    return buf ;
}



/*-------------------------------------------------------------------------*/
/**
 @brief	Opens up a gnuplot session, ready to receive commands.
 @return	Newly allocated gnuplot control structure.
 
 This opens up a new gnuplot session, ready for input. The struct
 controlling a gnuplot session should remain opaque and only be
 accessed through the provided functions.
 
 The session must be closed using gnuplot_close().
 */
/*--------------------------------------------------------------------------*/

gnuplot_ctrl * gnuplot_init(void)
{
    gnuplot_ctrl *  handle ;
	
    if (getenv("DISPLAY") == NULL) {
        fprintf(stderr, "cannot find DISPLAY variable: is it set?\n") ;
    }
	if (gnuplot_get_program_path("gnuplot")==NULL) {
		fprintf(stderr, "cannot find gnuplot in your PATH");
		return NULL ;
	}
	
    /* 
     * Structure initialization:
     */
    handle = (gnuplot_ctrl*)malloc(sizeof(gnuplot_ctrl)) ;
    handle->nplots = 0 ;
    gnuplot_setstyle(handle, "points") ;
    handle->ntmp = 0 ;
	
    handle->gnucmd = popen("gnuplot", "w") ;
    if (handle->gnucmd == NULL) {
        fprintf(stderr, "error starting gnuplot\n") ;
        free(handle) ;
        return NULL ;
    }
    return handle;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Closes a gnuplot session previously opened by gnuplot_init()
 @param	handle Gnuplot session control handle.
 @return	void
 
 Kills the child PID and deletes all opened temporary files.
 It is mandatory to call this function to close the handle, otherwise
 temporary files are not cleaned and child process might survive.
 
 */
/*--------------------------------------------------------------------------*/

void gnuplot_close(gnuplot_ctrl * handle)
{
    int     i ;
	
    if (pclose(handle->gnucmd) == -1) {
        fprintf(stderr, "problem closing communication to gnuplot\n") ;
        return ;
    }
    if (handle->ntmp) {
        for (i=0 ; i<handle->ntmp ; i++) {
            remove(handle->to_delete[i]) ;
        }
    }
    free(handle) ;
    return ;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Sends a command to an active gnuplot session.
 @param	handle Gnuplot session control handle
 @param	cmd    Command to send, same as a printf statement.
 
 This sends a string to an active gnuplot session, to be executed.
 There is strictly no way to know if the command has been
 successfully executed or not.
 The command syntax is the same as printf.
 
 Examples:
 
 @code
 gnuplot_cmd(g, "plot %d*x", 23.0);
 gnuplot_cmd(g, "plot %g * cos(%g * x)", 32.0, -3.0);
 @endcode
 
 Since the communication to the gnuplot process is run through
 a standard Unix pipe, it is only unidirectional. This means that
 it is not possible for this interface to query an error status
 back from gnuplot.
 */
/*--------------------------------------------------------------------------*/

void gnuplot_cmd(gnuplot_ctrl *  handle, char *  cmd, ...)
{
    va_list ap ;
    char    local_cmd[GP_CMD_SIZE];
	
    va_start(ap, cmd);
    vsprintf(local_cmd, cmd, ap);
    va_end(ap);
	
    strcat(local_cmd, "\n");
	
    fputs(local_cmd, handle->gnucmd) ;
    fflush(handle->gnucmd) ;
    return ;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Change the plotting style of a gnuplot session.
 @param	h Gnuplot session control handle
 @param	plot_style Plotting-style to use (character string)
 @return	void
 
 The provided plotting style is a character string. It must be one of
 the following:
 
 - lines
 - points
 - linespoints
 - impulses
 - dots
 - steps
 - errorbars
 - boxes
 - boxeserrorbars
 */
/*--------------------------------------------------------------------------*/

void gnuplot_setstyle(gnuplot_ctrl * h, char * plot_style) 
{
    if (strcmp(plot_style, "lines") &&
        strcmp(plot_style, "points") &&
        strcmp(plot_style, "linespoints") &&
        strcmp(plot_style, "impulses") &&
        strcmp(plot_style, "dots") &&
        strcmp(plot_style, "steps") &&
        strcmp(plot_style, "errorbars") &&
        strcmp(plot_style, "boxes") &&
        strcmp(plot_style, "boxerrorbars")) {
        fprintf(stderr, "warning: unknown requested style: using points\n") ;
        strcpy(h->pstyle, "points") ;
    } else {
        strcpy(h->pstyle, plot_style) ;
    }
    return ;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Sets the x label of a gnuplot session.
 @param	h Gnuplot session control handle.
 @param	label Character string to use for X label.
 @return	void
 
 Sets the x label for a gnuplot session.
 */
/*--------------------------------------------------------------------------*/

void gnuplot_set_xlabel(gnuplot_ctrl * h, char * label)
{
    char    cmd[GP_CMD_SIZE] ;
	
    sprintf(cmd, "set xlabel \"%s\"", label) ;
    gnuplot_cmd(h, cmd) ;
    return ;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Sets the y label of a gnuplot session.
 @param	h Gnuplot session control handle.
 @param	label Character string to use for Y label.
 @return	void
 
 Sets the y label for a gnuplot session.
 */
/*--------------------------------------------------------------------------*/

void gnuplot_set_ylabel(gnuplot_ctrl * h, char * label)
{
    char    cmd[GP_CMD_SIZE] ;
	
    sprintf(cmd, "set ylabel \"%s\"", label) ;
    gnuplot_cmd(h, cmd) ;
    return ;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Resets a gnuplot session (next plot will erase previous ones).
 @param	h Gnuplot session control handle.
 @return	void
 
 Resets a gnuplot session, i.e. the next plot will erase all previous
 ones.
 */
/*--------------------------------------------------------------------------*/

void gnuplot_resetplot(gnuplot_ctrl * h)
{
    int     i ;
    if (h->ntmp) {
        for (i=0 ; i<h->ntmp ; i++) {
            remove(h->to_delete[i]) ;
        }
    }
    h->ntmp = 0 ;
    h->nplots = 0 ;
    return ;
}



/*-------------------------------------------------------------------------*/
/**
 @brief	Plots a 2d graph from a list of doubles.
 @param	handle	Gnuplot session control handle.
 @param	d		Array of doubles.
 @param	n		Number of values in the passed array.
 @param	title	Title of the plot.
 @return	void
 
 Plots out a 2d graph from a list of doubles. The x-coordinate is the
 index of the double in the list, the y coordinate is the double in
 the list.
 
 Example:
 
 @code
 gnuplot_ctrl    *h ;
 double          d[50] ;
 int             i ;
 
 h = gnuplot_init() ;
 for (i=0 ; i<50 ; i++) {
 d[i] = (double)(i*i) ;
 }
 gnuplot_plot_x(h, d, 50, "parabola") ;
 sleep(2) ;
 gnuplot_close(h) ;
 @endcode
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_x(
					gnuplot_ctrl    *   handle,
					double          *   d,
					int                 n,
					char            *   title
)
{
    int     i ;
	int		tmpfd ;
    char    name[128] ;
    char    cmd[GP_CMD_SIZE] ;
    char    line[GP_CMD_SIZE] ;
	
	
	if (handle==NULL || d==NULL || (n<1)) return ;
	
    /* Open one more temporary file? */
    if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
        fprintf(stderr,
                "maximum # of temporary files reached (%d): cannot open more",
                GP_MAX_TMP_FILES) ;
        return ;
    }
	
    /* Open temporary file for output   */
	sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
    if ((tmpfd=mkstemp(name))==-1) {
        fprintf(stderr,"cannot create temporary file: exiting plot") ;
        return ;
    }
	
    /* Store file name in array for future deletion */
    strcpy(handle->to_delete[handle->ntmp], name) ;
    handle->ntmp ++ ;
    /* Write data to this file  */
    for (i=0 ; i<n ; i++) {
		sprintf(line, "%g\n", d[i]);
		write(tmpfd, line, strlen(line));
    }
    close(tmpfd) ;
	
    /* Command to be sent to gnuplot    */
    if (handle->nplots > 0) {
        strcpy(cmd, "replot") ;
    } else {
        strcpy(cmd, "plot") ;
    }
    
    if (title == NULL) {
        sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle) ;
    } else {
        sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
				title, handle->pstyle) ;
    }
	
    /* send command to gnuplot  */
    gnuplot_cmd(handle, line) ;
    handle->nplots++ ;
    return ;
}



/*-------------------------------------------------------------------------*/
/**
 @brief	Plot a 2d graph from a list of points.
 @param	handle		Gnuplot session control handle.
 @param	x			Pointer to a list of x coordinates.
 @param	y			Pointer to a list of y coordinates.
 @param	n			Number of doubles in x (assumed the same as in y).
 @param	title		Title of the plot.
 @return	void
 
 Plots out a 2d graph from a list of points. Provide points through a list
 of x and a list of y coordinates. Both provided arrays are assumed to
 contain the same number of values.
 
 @code
 gnuplot_ctrl    *h ;
 double			x[50] ;
 double			y[50] ;
 int             i ;
 
 h = gnuplot_init() ;
 for (i=0 ; i<50 ; i++) {
 x[i] = (double)(i)/10.0 ;
 y[i] = x[i] * x[i] ;
 }
 gnuplot_plot_xy(h, x, y, 50, "parabola") ;
 sleep(2) ;
 gnuplot_close(h) ;
 @endcode
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_xy(
					 gnuplot_ctrl    *   handle,
					 double			*	x,
					 double			*	y,
					 int                 n,
					 char            *   title
)
{
    int     i ;
	int		tmpfd ;
    char    name[128] ;
    char    cmd[GP_CMD_SIZE] ;
    char    line[GP_CMD_SIZE] ;
	
	if (handle==NULL || x==NULL || y==NULL || (n<1)) return ;
	
    /* Open one more temporary file? */
    if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
        fprintf(stderr,
                "maximum # of temporary files reached (%d): cannot open more",
                GP_MAX_TMP_FILES) ;
        return ;
    }
	
    /* Open temporary file for output   */
	sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
    if ((tmpfd=mkstemp(name))==-1) {
        fprintf(stderr,"cannot create temporary file: exiting plot") ;
        return ;
    }
    /* Store file name in array for future deletion */
    strcpy(handle->to_delete[handle->ntmp], name) ;
    handle->ntmp ++ ;
	
    /* Write data to this file  */
    for (i=0 ; i<n; i++) {
        sprintf(line, "%g %g\n", x[i], y[i]) ;
		write(tmpfd, line, strlen(line));
    }
    close(tmpfd) ;
	
    /* Command to be sent to gnuplot    */
    if (handle->nplots > 0) {
        strcpy(cmd, "replot") ;
    } else {
        strcpy(cmd, "plot") ;
    }
    
    if (title == NULL) {
        sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle) ;
    } else {
        sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
				title, handle->pstyle) ;
    }
	
    /* send command to gnuplot  */
    gnuplot_cmd(handle, line) ;
    handle->nplots++ ;
    return ;
}



/*-------------------------------------------------------------------------*/
/**
 @brief	Open a new session, plot a signal, close the session.
 @param	title	Plot title
 @param	style	Plot style
 @param	label_x	Label for X
 @param	label_y	Label for Y
 @param	x		Array of X coordinates
 @param	y		Array of Y coordinates (can be NULL)
 @param	n		Number of values in x and y.
 @return
 
 This function opens a new gnuplot session, plots the provided
 signal as an X or XY signal depending on a provided y, waits for
 a carriage return on stdin and closes the session.
 
 It is Ok to provide an empty title, empty style, or empty labels for
 X and Y. Defaults are provided in this case.
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_once(
					   char	*	title,
					   char	*	style,
					   char	*	label_x,
					   char	*	label_y,
					   double	*	x,
					   double	*	y,
					   int			n
)
{
	gnuplot_ctrl	*	handle ;
	
	if (x==NULL || n<1) return ;
	
	if ((handle = gnuplot_init()) == NULL) return ;
	if (style!=NULL) {
		gnuplot_setstyle(handle, style);
	} else {
		gnuplot_setstyle(handle, "lines");
	}
	if (label_x!=NULL) {
		gnuplot_set_xlabel(handle, label_x);
	} else {
		gnuplot_set_xlabel(handle, "X");
	}
	if (label_y!=NULL) {
		gnuplot_set_ylabel(handle, label_y);
	} else {
		gnuplot_set_ylabel(handle, "Y");
	}
	if (y==NULL) {
		gnuplot_plot_x(handle, x, n, title);
	} else {
		gnuplot_plot_xy(handle, x, y, n, title);
	}
	printf("press ENTER to continue\n");
	while (getchar()!='\n') {}
	gnuplot_close(handle);
	return ;
}




/*-------------------------------------------------------------------------*/
/**
 @brief	Plot a slope on a gnuplot session.
 @param	handle		Gnuplot session control handle.
 @param	a			Slope.
 @param	b			Intercept.
 @param	title		Title of the plot.
 @return	void
 
 Plot a slope on a gnuplot session. The provided slope has an
 equation of the form y=ax+b
 
 Example:
 
 @code
 gnuplot_ctrl    *   h ;
 double              a, b ;
 
 h = gnuplot_init() ;
 gnuplot_plot_slope(h, 1.0, 0.0, "unity slope") ;
 sleep(2) ;
 gnuplot_close(h) ;
 @endcode
 */
/*--------------------------------------------------------------------------*/


void gnuplot_plot_slope(
						gnuplot_ctrl    *   handle,
						double              a,
						double              b,
						char            *   title
)
{
    char    stitle[GP_TITLE_SIZE] ;
    char    cmd[GP_CMD_SIZE] ;
	
    if (title == NULL) {
        strcpy(stitle, "no title") ;
    } else {
        strcpy(stitle, title) ;
    }
	
    if (handle->nplots > 0) {
        sprintf(cmd, "replot %g * x + %g title \"%s\" with %s",
				a, b, title, handle->pstyle) ;
    } else {
        sprintf(cmd, "plot %g * x + %g title \"%s\" with %s",
				a, b, title, handle->pstyle) ;
    }
    gnuplot_cmd(handle, cmd) ;
    handle->nplots++ ;
    return ;
}


/*-------------------------------------------------------------------------*/
/**
 @brief	Plot a curve of given equation y=f(x).
 @param	h			Gnuplot session control handle.
 @param	equation	Equation to plot.
 @param	title		Title of the plot.
 @return	void
 
 Plots out a curve of given equation. The general form of the
 equation is y=f(x), you only provide the f(x) side of the equation.
 
 Example:
 
 @code
 gnuplot_ctrl    *h ;
 char            eq[80] ;
 
 h = gnuplot_init() ;
 strcpy(eq, "sin(x) * cos(2*x)") ;
 gnuplot_plot_equation(h, eq, "sine wave", normal) ;
 gnuplot_close(h) ;
 @endcode
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_equation(
						   gnuplot_ctrl    *   h,
						   char            *   equation,
						   char            *   title
)
{
    char    cmd[GP_CMD_SIZE];
    char    plot_str[GP_EQ_SIZE] ;
    char    title_str[GP_TITLE_SIZE] ;
	
    if (title == NULL) {
        strcpy(title_str, "no title") ;
    } else {
        strcpy(title_str, title) ;
    }
    if (h->nplots > 0) {
        strcpy(plot_str, "replot") ;
    } else {
        strcpy(plot_str, "plot") ;
    }
	
    sprintf(cmd, "%s %s title \"%s\" with %s", 
			plot_str, equation, title_str, h->pstyle) ;
    gnuplot_cmd(h, cmd) ;
    h->nplots++ ;
    return ;
}

/* vim: set ts=4 et sw=4 tw=75 */
```


kann mir evtl. jemand da weiterhelfen?

vielen dank


----------



## RedWing (23. April 2009)

Hallo,

bitte benutze das nächste mal die Codetags wenn du Code einfügst. So wie er jetzt ist, ist dein Beitrag unzumutbar für andere. Außerdem, um Augenkrebs zu verhindern, wäre es super wenn du die Groß/Kleinschreibung beachten würdest. Wenn du das beachtest steigt  auch die Wahrscheinlichkeit hier Hilfe zu bekommen.

Zu deinem Problem:

1.) Musst du das Programm gnuplot installieren, bevor du gnuplot_i verwenden kannst.
2.) Ist es unschöner Stil Sourcedateien zu inkludieren. Du kannst gnuplot_i.c mit Hilfe des Kommandos

```
gcc -c gnuplot_i.c -o gnuplot_i.o
```
 kompilieren. Dadurch erzeugst du eine Objektdatei namens gnuplot_i.o. Diese vorkompilierte Datei kannst du dann zu deiner Anwendung direkt beim Kompileraufruf mit hinzubinden:

```
gcc test.c gnuplot_i.o -o test_program
```
 Und es sollte funktionieren.

Gruß,
RedWing


----------



## Poolshark (24. April 2009)

Sorry! Werde ich natürlich in Zukunft beachten.

Ich weiß dass es unschön ist die Sourcedateien zu inkludieren, aber wie gesagt ich bin kein Programmierer und bis jetzt war es für mich einfach einfacher das Problem so zu lösen da ich ja keine großen Programme schreibe und ich nicht zu sehr auf die Reihung der einzelnen Sourcedateien achten muss. Aber ich verstehe das Problem und werde auch hier in Zukunft etwas genauer sein... 
Anyway, natürlich hatte ich gnuplot bereits vorher installiert - es ist bei mir auch ständig in Gebrauch, funktioniert also einwandfrei.

Um Missverständnisse auszuräumen, hier nocheinmal meine Fehlermeldung:



> [Session started at 2009-04-24 00:08:14 +0200.]
> *cannot find gnuplot in your PATH*
> [Session started at 2009-04-24 00:08:14 +0200.]
> Loading program into debugger…
> ...




Danke auf jeden Fall für die schnelle Antwort!

LG


----------



## RedWing (24. April 2009)

Hallo,

kein Proble. Wenn gnuplot bereits installiert ist,  ist es was anderes. Wie ist das bei MacOS, gibt es da eine PATH Variable? Wie bentutz du das Programm gewöhnlich? In welchem Verzeichnis liegt das gnuplot Binary? Wenn es eine PATH Variable gibt, zeigt sie auf das Verzeichnis indem es liegt? 

Gruß,
RedWing


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## Poolshark (24. April 2009)

Da Mac OS X ja auf einer UNIX Shell basiert und sollte es schon so etwas wie eine PATH Variable geben. Leider konnte ich bei mir aber keine finden und anscheinend, wie ich aus einem anderen Forum entnommen habe, muss man sich diese Variable *.bashrc* auch selbst anlegen.
GNUPLOT verwende ich normalerweise einfach vom Terminal aus:



> Last login: Wed Apr 22 07:46:37 on ttys000
> Flows-Apfal:~ florianragossnig$ gnuplot
> 
> G N U P L O T
> ...


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## RedWing (24. April 2009)

Hallo,

Was  sagt denn "echo $PATH"?

Lässt sich das Verzeichnis des gnuplot - Binaries lokalisieren? Wenn ja, versuch doch mal folgendes:


```
export PATH=$PATH:/dein/verz/zu/gnuplotbinary/
./dein_program
```

HTH,
RedWing


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## Poolshark (24. April 2009)

Hi,


```
Last login: Fri Apr 24 17:15:16 on ttys001
Flows-Apfal:~ florianragossnig$ echo $PATH
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/usr/texbin:/usr/local/bin
```

Das Verzeichnis für die GNUPLOT- Binaries konnte ich leider nicht lokalisieren... 

Vielen Dank für deine schnelle Hilfe!


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## deepthroat (24. April 2009)

Hi.





Poolshark hat gesagt.:


> Hi,
> 
> 
> ```
> ...


Gib mal "type gnuplot" in der Shell ein. Dann siehst du das Verzeichnis.

Von wo aus startest du denn dein Programm? Kann durchaus sein, das die PATH Variable in der Shell anders ist als z.B. von deiner IDE aus...

Gruß


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## Poolshark (24. April 2009)

```
Flows-Apfal:~ florianragossnig$ type gnuplot
gnuplot is /usr/local/bin/gnuplot
Flows-Apfal:~ florianragossnig
```

sollte ich mit dem type Befehl nicht auch den Pfad meiner IDE ausmachen können?

habs probiert:


```
Flows-Apfal:~ florianragossnig$ type Xcode
-bash: type: Xcode: not found
Flows-Apfal:~ florianragossnig$
```

Gute Frage von wo aus ich mein Programm starte... Xcode verwende ich ganz normal als OS X Oberfläche.

Tut mir leid dass ich nicht mehr Informationen geben kann, wie du siehst halten sich meine Kenntnisse über Shell basierte Steuerung von OS X sehr in Grenzen...


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## deepthroat (24. April 2009)

Poolshark hat gesagt.:


> ```
> Flows-Apfal:~ florianragossnig$ type gnuplot
> gnuplot is /usr/local/bin/gnuplot
> Flows-Apfal:~ florianragossnig
> ...


Nur wenn die ausführbare Datei auch Xcode heißt (und nicht xcode oder XCode oder xcode-bin oder....) und falls diese sich auch in einem Verzeichnis befindet was in der PATH Variable aufgelistet ist.

Warum startest du dein Programm nicht einfach von der Shell aus?

Mit der getenv Funktion kannst du dir in deinem Programm die PATH Variable geben lassen. Mit der setenv Funktion kannst du das /usr/local/bin Verzeichnis noch zur PATH Variable hinzufügen, falls es notwendig ist. Siehe http://www.manpagez.com/man/3/getenv/

Gruß


----------

