使用execlp()遇到麻烦 [英] getting trouble with execlp()
本文介绍了使用execlp()遇到麻烦的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在使用execlp来实现基于网络的命令，但是它不起作用.我正在使用
execlp("telnet 0 5000","telnet 0 5000",(char *)NULL);
delwin(menubar);
delwin(messagebar);
endwin();
但是它不能正常工作，如果我用ls替换telnet 0 5000它将起作用，但是输出出现在GUI上的同一屏幕上，并且noecho get自动激活，并且ls的输出以一种非常不寻常的方式出现. /p>
下面是我的完整代码.
#include <curses.h>
#include <stdlib.h>
#include<stdio.h>
#define ENTER 10
#define ESCAPE 27
void init_curses()
{
initscr();
start_color();
init_pair(1,COLOR_WHITE,COLOR_
BLUE);
init_pair(2,COLOR_BLUE,COLOR_WHITE);
init_pair(3,COLOR_RED,COLOR_WHITE);
curs_set(0);
//noecho();
keypad(stdscr,TRUE);
}
void draw_menubar(WINDOW *menubar)
{
wbkgd(menubar,COLOR_PAIR(2));
waddstr(menubar,"PARALLEL");
wattron(menubar,COLOR_PAIR(3));
waddstr(menubar,"CON.");
wattroff(menubar,COLOR_PAIR(3));
wmove(menubar,0,20);
waddstr(menubar,"SERIAL");
wattron(menubar,COLOR_PAIR(3));
waddstr(menubar,"CON.");
wattroff(menubar,COLOR_PAIR(3));
}
WINDOW **draw_menu(int start_col)
{
WINDOW **items;
items=(WINDOW **)malloc(9*sizeof(WINDOW *));
items[0]=newwin(10,19,1,start_col);
wbkgd(items[0],COLOR_PAIR(2));
box(items[0],ACS_VLINE,ACS_HLINE);
items[1]=subwin(items[0],1,17,2,start_col+1);
wprintw(items[1],"Shailendra singh",1);
items[2]=subwin(items[0],1,17,3,start_col+1);
wprintw(items[2],"THIVNENT TECH",2);
items[3]=subwin(items[0],1,17,4,start_col+1);
wprintw(items[3],"THINCLIENT",3);
items[4]=subwin(items[0],1,17,5,start_col+1);
wprintw(items[4],"SOLARCOMPUTING",4);
items[5]=subwin(items[0],1,17,6,start_col+1);
wprintw(items[5],"TECHNOCRATS",5);
items[6]=subwin(items[0],1,17,7,start_col+1);
wprintw(items[6],"SENSORS",6);
items[7]=subwin(items[0],1,17,8,start_col+1);
wprintw(items[7],"NCURSESLIB",7);
items[8]=subwin(items[0],1,17,9,start_col+1);
wprintw(items[8],"GCC COMPILER",8);
wbkgd(items[1],COLOR_PAIR(1));
wrefresh(items[0]);
return items;
}
void write_data0()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.0 \n", fp);
fputs("Server type = R ",ft);
fclose(ft);
fclose(fp);
}
void write_data1()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1;}
fputs("172.16.254.1 \n", fp);
fputs("Server type = T ",ft);
fclose(ft);
fclose(fp);
}
void write_data2()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1;}
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.2 \n", fp);
fputs("Server type = C ",ft);
fclose(ft);
fclose(fp);
}
void write_data3()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.3 \n", fp);
fputs("Server type = R ",ft);
fclose(ft);
fclose(fp);
}
void write_data4()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1;}
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.4 \n", fp);
fputs("Server type = T ",ft);
fclose(ft);
fclose(fp);
}
void write_data5()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.5 \n", fp);
fputs("Server type = C ", ft);
fclose(ft);
fclose(fp);
}
void write_data6()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1;}
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.6 \n", fp);
fputs("Server type = R ",ft);
fclose(ft);
fclose(fp);
}
void write_data7()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.7 \n", fp);
fputs("Server type = T ",ft);
fclose(ft);
fclose(fp);
}
WINDOW **draw_menu1(int start_col)
{
WINDOW **items;
items=(WINDOW **)malloc(9*sizeof(WINDOW *));
items[9]=newwin(10,19,1,start_col);
wbkgd(items[9],COLOR_PAIR(2));
box(items[9],ACS_VLINE,ACS_HLINE);
items[1]=subwin(items[9],1,17,2,start_col+1);
wprintw(items[1],"SHAILENDRA SINGH",1);
items[2]=subwin(items[9],1,17,3,start_col+1);
wprintw(items[2],"thivnent tech",2);
items[3]=subwin(items[9],1,17,4,start_col+1);
wprintw(items[3],"THINCLIENT",3);
items[4]=subwin(items[9],1,17,5,start_col+1);
wprintw(items[4],"SOLARCOMPUTING",4);
items[5]=subwin(items[9],1,17,6,start_col+1);
wprintw(items[5],"TECHNOCRATS",5);
items[6]=subwin(items[9],1,17,7,start_col+1);
wprintw(items[6],"SENSORS",6);
items[7]=subwin(items[9],1,17,8,start_col+1);
wprintw(items[7],"NCURSESLIB",7);
items[8]=subwin(items[9],1,17,9,start_col+1);
wprintw(items[8],"GCC COMPILER",8);
wbkgd(items[1],COLOR_PAIR(1));
wrefresh(items[9]);
return items;
}
void delete_menu(WINDOW **items,int count)
{
int i;
for (i=0;i<count;i++)
delwin(items[i]);
free(items);
}
int scroll_menu(WINDOW **items,int count,int menu_start_col)
{
int key;
int selected=0;
while (1) {
key=getch();
if (key==KEY_DOWN || key==KEY_UP) {
wbkgd(items[selected+1],COLOR_PAIR(2));
wnoutrefresh(items[selected+1]);
if (key==KEY_DOWN) {
selected=(selected+1) % count;
} else {
selected=(selected+count-1) % count;
}
wbkgd(items[selected+1],COLOR_PAIR(1));
wnoutrefresh(items[selected+1]);
doupdate();
} else if (key==KEY_LEFT || key==KEY_RIGHT) {
delete_menu(items,count+1);
touchwin(stdscr);
refresh();
items=draw_menu(20-menu_start_col);
return scroll_menu(items,8,20-menu_start_col);
} else if (key==ESCAPE) {
return -1;
} else if (key==ENTER) {
return selected;
}
}
}
int main()
{
int key;
WINDOW *menubar,*messagebar;
init_curses();
bkgd(COLOR_PAIR(1));
menubar=subwin(stdscr,1,80,0,0);
messagebar=subwin(stdscr,1,79,23,1);
draw_menubar(menubar);
move(2,1);
printw("Press F1 or F2 to open the menus. ");
printw("ESC quits.");
refresh();
do {
int selected_item;
WINDOW **menu_items;
key=getch();
werase(messagebar);
wrefresh(messagebar);
if (key==KEY_F(1)) {
menu_items=draw_menu(0);
selected_item=scroll_menu(menu_items,8,0);
delete_menu(menu_items,9);
if (selected_item<0)
wprintw(messagebar,"You haven't selected any item.");
else if(selected_item==0){
wprintw(messagebar,"You have selected menu SHAILENDRA SINGH.",1);
write_data0();
if(fork())
wait(0);
else
execlp("clear","clear",(char *)NULL);
execlp("ls","ls",(char *)NULL);
execlp("konsole","konsole",(char *)NULL);
ESCAPE;
refresh();
delwin(menubar);
delwin(messagebar);
endwin();
}
else if(selected_item==1){
wprintw(messagebar,"You have selected menu THINVENT TECH.",2);
write_data1();
}
else if(selected_item==2){
wprintw(messagebar,"You have selected menu THINCLIENT.",3);
write_data2();
}
else if(selected_item==3){
wprintw(messagebar,"You have selected menu SOLAR COMPUTING",4);
write_data3();
}
else if(selected_item==4){
wprintw(messagebar,"You have selected menu TECHNOCRATS.",5);
write_data4();
}
else if(selected_item==5){
wprintw(messagebar,"You have selected menu SENSORS.",6);
write_data5();
}
else if(selected_item==6){
wprintw(messagebar,"You have selected menu NCURSESLIB.",7);
write_data6();
}
else if(selected_item==7){
wprintw(messagebar,"You have selected menu GCCCOMPILER.",8);
write_data7();
}
touchwin(stdscr);
refresh();
}
else if (key==KEY_F(2)) {
menu_items=draw_menu1(20);
selected_item=scroll_menu(menu_items,8,20);
delete_menu(menu_items,9);
if (selected_item<0)
wprintw(messagebar,"You haven't selected any item.");
else
wprintw(messagebar,
"You have selected menu item %d.",selected_item+1);
touchwin(stdscr);
refresh();
}}
while (key!=ESCAPE);
delwin(menubar);
delwin(messagebar);
endwin();
return 0;
}
解决方案
您应该分别传递参数，第一个参数是要执行的文件的名称:
execlp("/usr/bin/telnet", "telnet", "0", "5000", (char *)NULL);
man execlp(3)
int execlp(const char * file，const char * arg，...);
这些功能的初始参数是以下文件的名称: 待执行. const char * arg及其后的省略号 execl()，execlp()和execle()函数可以认为是arg0， arg1，...，argn .
I am using execlp to implement a net based command but its not working.I am using
execlp("telnet 0 5000","telnet 0 5000",(char *)NULL);
delwin(menubar);
delwin(messagebar);
endwin();
but its not working else than that if i replace telnet 0 5000 with ls it will work but the output comes on the same screen means on the GUI and noecho get activates automatically and output of ls comes in a pretty unusual manner.
below is my full code .
#include <curses.h>
#include <stdlib.h>
#include<stdio.h>
#define ENTER 10
#define ESCAPE 27
void init_curses()
{
initscr();
start_color();
init_pair(1,COLOR_WHITE,COLOR_
BLUE);
init_pair(2,COLOR_BLUE,COLOR_WHITE);
init_pair(3,COLOR_RED,COLOR_WHITE);
curs_set(0);
//noecho();
keypad(stdscr,TRUE);
}
void draw_menubar(WINDOW *menubar)
{
wbkgd(menubar,COLOR_PAIR(2));
waddstr(menubar,"PARALLEL");
wattron(menubar,COLOR_PAIR(3));
waddstr(menubar,"CON.");
wattroff(menubar,COLOR_PAIR(3));
wmove(menubar,0,20);
waddstr(menubar,"SERIAL");
wattron(menubar,COLOR_PAIR(3));
waddstr(menubar,"CON.");
wattroff(menubar,COLOR_PAIR(3));
}
WINDOW **draw_menu(int start_col)
{
WINDOW **items;
items=(WINDOW **)malloc(9*sizeof(WINDOW *));
items[0]=newwin(10,19,1,start_col);
wbkgd(items[0],COLOR_PAIR(2));
box(items[0],ACS_VLINE,ACS_HLINE);
items[1]=subwin(items[0],1,17,2,start_col+1);
wprintw(items[1],"Shailendra singh",1);
items[2]=subwin(items[0],1,17,3,start_col+1);
wprintw(items[2],"THIVNENT TECH",2);
items[3]=subwin(items[0],1,17,4,start_col+1);
wprintw(items[3],"THINCLIENT",3);
items[4]=subwin(items[0],1,17,5,start_col+1);
wprintw(items[4],"SOLARCOMPUTING",4);
items[5]=subwin(items[0],1,17,6,start_col+1);
wprintw(items[5],"TECHNOCRATS",5);
items[6]=subwin(items[0],1,17,7,start_col+1);
wprintw(items[6],"SENSORS",6);
items[7]=subwin(items[0],1,17,8,start_col+1);
wprintw(items[7],"NCURSESLIB",7);
items[8]=subwin(items[0],1,17,9,start_col+1);
wprintw(items[8],"GCC COMPILER",8);
wbkgd(items[1],COLOR_PAIR(1));
wrefresh(items[0]);
return items;
}
void write_data0()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.0 \n", fp);
fputs("Server type = R ",ft);
fclose(ft);
fclose(fp);
}
void write_data1()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1;}
fputs("172.16.254.1 \n", fp);
fputs("Server type = T ",ft);
fclose(ft);
fclose(fp);
}
void write_data2()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1;}
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.2 \n", fp);
fputs("Server type = C ",ft);
fclose(ft);
fclose(fp);
}
void write_data3()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.3 \n", fp);
fputs("Server type = R ",ft);
fclose(ft);
fclose(fp);
}
void write_data4()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1;}
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.4 \n", fp);
fputs("Server type = T ",ft);
fclose(ft);
fclose(fp);
}
void write_data5()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.5 \n", fp);
fputs("Server type = C ", ft);
fclose(ft);
fclose(fp);
}
void write_data6()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1;}
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.6 \n", fp);
fputs("Server type = R ",ft);
fclose(ft);
fclose(fp);
}
void write_data7()
{FILE *fp,*ft;
fp = fopen("file.txt", "w");
ft = fopen("servertype.txt","w");
if(fp == NULL) {fprintf(stderr, "Cannot open \"file.txt\" for appending\n");
return 1; }
if(ft == NULL) {fprintf(stderr, "Cannot open \"servertype.txt\" for appending\n");
return 1; }
fputs("172.16.254.7 \n", fp);
fputs("Server type = T ",ft);
fclose(ft);
fclose(fp);
}
WINDOW **draw_menu1(int start_col)
{
WINDOW **items;
items=(WINDOW **)malloc(9*sizeof(WINDOW *));
items[9]=newwin(10,19,1,start_col);
wbkgd(items[9],COLOR_PAIR(2));
box(items[9],ACS_VLINE,ACS_HLINE);
items[1]=subwin(items[9],1,17,2,start_col+1);
wprintw(items[1],"SHAILENDRA SINGH",1);
items[2]=subwin(items[9],1,17,3,start_col+1);
wprintw(items[2],"thivnent tech",2);
items[3]=subwin(items[9],1,17,4,start_col+1);
wprintw(items[3],"THINCLIENT",3);
items[4]=subwin(items[9],1,17,5,start_col+1);
wprintw(items[4],"SOLARCOMPUTING",4);
items[5]=subwin(items[9],1,17,6,start_col+1);
wprintw(items[5],"TECHNOCRATS",5);
items[6]=subwin(items[9],1,17,7,start_col+1);
wprintw(items[6],"SENSORS",6);
items[7]=subwin(items[9],1,17,8,start_col+1);
wprintw(items[7],"NCURSESLIB",7);
items[8]=subwin(items[9],1,17,9,start_col+1);
wprintw(items[8],"GCC COMPILER",8);
wbkgd(items[1],COLOR_PAIR(1));
wrefresh(items[9]);
return items;
}
void delete_menu(WINDOW **items,int count)
{
int i;
for (i=0;i<count;i++)
delwin(items[i]);
free(items);
}
int scroll_menu(WINDOW **items,int count,int menu_start_col)
{
int key;
int selected=0;
while (1) {
key=getch();
if (key==KEY_DOWN || key==KEY_UP) {
wbkgd(items[selected+1],COLOR_PAIR(2));
wnoutrefresh(items[selected+1]);
if (key==KEY_DOWN) {
selected=(selected+1) % count;
} else {
selected=(selected+count-1) % count;
}
wbkgd(items[selected+1],COLOR_PAIR(1));
wnoutrefresh(items[selected+1]);
doupdate();
} else if (key==KEY_LEFT || key==KEY_RIGHT) {
delete_menu(items,count+1);
touchwin(stdscr);
refresh();
items=draw_menu(20-menu_start_col);
return scroll_menu(items,8,20-menu_start_col);
} else if (key==ESCAPE) {
return -1;
} else if (key==ENTER) {
return selected;
}
}
}
int main()
{
int key;
WINDOW *menubar,*messagebar;
init_curses();
bkgd(COLOR_PAIR(1));
menubar=subwin(stdscr,1,80,0,0);
messagebar=subwin(stdscr,1,79,23,1);
draw_menubar(menubar);
move(2,1);
printw("Press F1 or F2 to open the menus. ");
printw("ESC quits.");
refresh();
do {
int selected_item;
WINDOW **menu_items;
key=getch();
werase(messagebar);
wrefresh(messagebar);
if (key==KEY_F(1)) {
menu_items=draw_menu(0);
selected_item=scroll_menu(menu_items,8,0);
delete_menu(menu_items,9);
if (selected_item<0)
wprintw(messagebar,"You haven't selected any item.");
else if(selected_item==0){
wprintw(messagebar,"You have selected menu SHAILENDRA SINGH.",1);
write_data0();
if(fork())
wait(0);
else
execlp("clear","clear",(char *)NULL);
execlp("ls","ls",(char *)NULL);
execlp("konsole","konsole",(char *)NULL);
ESCAPE;
refresh();
delwin(menubar);
delwin(messagebar);
endwin();
}
else if(selected_item==1){
wprintw(messagebar,"You have selected menu THINVENT TECH.",2);
write_data1();
}
else if(selected_item==2){
wprintw(messagebar,"You have selected menu THINCLIENT.",3);
write_data2();
}
else if(selected_item==3){
wprintw(messagebar,"You have selected menu SOLAR COMPUTING",4);
write_data3();
}
else if(selected_item==4){
wprintw(messagebar,"You have selected menu TECHNOCRATS.",5);
write_data4();
}
else if(selected_item==5){
wprintw(messagebar,"You have selected menu SENSORS.",6);
write_data5();
}
else if(selected_item==6){
wprintw(messagebar,"You have selected menu NCURSESLIB.",7);
write_data6();
}
else if(selected_item==7){
wprintw(messagebar,"You have selected menu GCCCOMPILER.",8);
write_data7();
}
touchwin(stdscr);
refresh();
}
else if (key==KEY_F(2)) {
menu_items=draw_menu1(20);
selected_item=scroll_menu(menu_items,8,20);
delete_menu(menu_items,9);
if (selected_item<0)
wprintw(messagebar,"You haven't selected any item.");
else
wprintw(messagebar,
"You have selected menu item %d.",selected_item+1);
touchwin(stdscr);
refresh();
}}
while (key!=ESCAPE);
delwin(menubar);
delwin(messagebar);
endwin();
return 0;
}
解决方案
you should pass arguments separately, and the first argument is the name of the file to be executed:
execlp("/usr/bin/telnet", "telnet", "0", "5000", (char *)NULL);
man execlp(3)
int execlp(const char *file, const char *arg, ...);
The initial argument for these functions is the name of a file that is to be executed. The const char *arg and subsequent ellipses in the execl(), execlp(), and execle() functions can be thought of as arg0, arg1, ..., argn.
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