perl使用system調(diào)用history返回值為-1

hutule110

1. 
   
2. use strict;
   
3. #!/usr/bin/perl -w
   
4. print system 'history';
   

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打印出來的值為 -1;

1. 
   
2. use strict;
   
3. #!/usr/bin/perl -w
   
4. print system 'ls -l';
   

復(fù)制代碼

打印出來是 ls -l的效果.
想知道為什么會有這種差異?

hutule110

用bash也是同樣的效果,history這個命令和ls 這樣的命令有啥區(qū)別么?{:3_186:}

gaochong

看看shell環(huán)境

hutule110

1. 
   
2. declare -x ACLOCAL_FLAGS="-I /opt/gnome/share/aclocal"
   
3. declare -x COLORTERM="1"
   
4. declare -x CPU="i686"
   
5. declare -x CSHEDIT="emacs"
   
6. declare -x ENV="/etc/bash.bashrc"
   
7. declare -x FROM_HEADER=""
   
8. declare -x GNOME2_PATH="/usr/local:/opt/gnome:/usr"
   
9. declare -x GROFF_NO_SGR="yes"
   
10. declare -x GTK_PATH="/usr/local/lib/gtk-2.0:/opt/gnome/lib/gtk-2.0:/usr/lib/gtk-2.0"
    
11. declare -x G_BROKEN_FILENAMES="1"
    
12. declare -x G_FILENAME_ENCODING="@locale,UTF-8,GB2312,GB18030,GBK,ISO-8859-1"
    
13. declare -x HISTSIZE="1000"
    
14. declare -x HOME="/root"
    
15. declare -x HOST=""
    
16. declare -x HOSTNAME="feixue"
    
17. declare -x HOSTTYPE="i386"
    
18. declare -x INFODIR="/usr/local/info:/usr/share/info:/usr/info"
    
19. declare -x INFOPATH="/usr/local/info:/usr/share/info:/usr/info:/opt/gnome/share/info"
    
20. declare -x INPUTRC="/etc/inputrc"
    
21. declare -x ISR40_HOME="/opt/xisr40"
    
22. declare -x LANG="zh_CN.UTF-8"
    
23. declare -x LC_ALL="C"
    
24. declare -x LD_LIBRARY_PATH="/opt/xisr40/lib:"
    
25. declare -x LESS="-M -I"
    
26. declare -x LESSCLOSE="lessclose.sh %s %s"
    
27. declare -x LESSKEY="/etc/lesskey.bin"
    
28. declare -x LESSOPEN="lessopen.sh %s"
    
29. declare -x LESS_ADVANCED_PREPROCESSOR="no"
    
30. declare -x LOGNAME="root"
    
31. declare -x LS_COLORS="no=00:fi=00:di=01;34:ln=00;36:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=41;33;01:ex=00;32:*.cmd=00;32:*.exe=01;32:*.com=01;32:*.bat=01;32:*.btm=01;32:*.dll=01;32:*.tar=00;31:*.tbz=00;31:*.tgz=00;31:*.rpm=00;31:*.deb=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.zoo=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.tb2=00;31:*.tz2=00;31:*.tbz2=00;31:*.avi=01;35:*.bmp=01;35:*.fli=01;35:*.gif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mng=01;35:*.mov=01;35:*.mpg=01;35:*.pcx=01;35:*.pbm=01;35:*.pgm=01;35:*.png=01;35:*.ppm=01;35:*.tga=01;35:*.tif=01;35:*.xbm=01;35:*.xpm=01;35:*.dl=01;35:*.gl=01;35:*.wmv=01;35:*.aiff=00;32:*.au=00;32:*.mid=00;32:*.mp3=00;32:*.ogg=00;32:*.voc=00;32:*.wav=00;32:"
    
32. declare -x LS_OPTIONS="-A -N --color=tty -T 0"
    
33. declare -x MACHTYPE="i686-suse-linux"
    
34. declare -x MAIL="/var/mail/root"
    
35. declare -x MANPATH="/usr/share/man:/usr/local/man:/usr/local/share/man:/usr/X11R6/man:/opt/gnome/share/man"
    
36. declare -x MINICOM="-c on"
    
37. declare -x MORE="-sl"
    
38. declare -x NNTPSERVER="news"
    
39. declare -x OLDPWD="/home/msp"
    
40. declare -x OSTYPE="linux"
    
41. declare -x PAGER="less"
    
42. declare -x PATH="/sbin:/usr/sbin:/usr/local/sbin:/opt/gnome/sbin:/root/bin:/usr/local/bin:/usr/bin:/usr/X11R6/bin:/bin:/usr/games:/opt/bin:/opt/gnome/bin:/opt/kde3/bin:/usr/lib/mit/bin:/usr/lib/mit/sbin"
    
43. declare -x PKG_CONFIG_PATH="/opt/gnome/lib/pkgconfig:/opt/gnome/share/pkgconfig"
    
44. declare -rx PROFILEREAD="true"
    
45. declare -x PWD="/home/msp/ctest"
    
46. declare -x PYTHONSTARTUP="/etc/pythonstart"
    
47. declare -x QT_SYSTEM_DIR="/usr/share/desktop-data"
    
48. declare -x SHELL="/bin/bash"
    
49. declare -x SHLVL="1"
    
50. declare -x SSH_CLIENT="192.168.70.48 1471 22"
    
51. declare -x SSH_CONNECTION="192.168.70.48 1471 192.168.72.78 22"
    
52. declare -x SSH_TTY="/dev/pts/0"
    
53. declare -x TERM="linux"
    
54. declare -x TEXINPUTS=":/root/.TeX:/usr/share/doc/.TeX:/usr/doc/.TeX"
    
55. declare -x USER="root"
    
56. declare -x WINDOWMANAGER="/usr/X11R6/bin/gnome"
    
57. declare -x XCURSOR_THEME="Industrial"
    
58. declare -x XDG_CONFIG_DIRS="/usr/local/etc/xdg/:/etc/xdg/:/etc/opt/gnome/xdg/"
    
59. declare -x XDG_DATA_DIRS="/usr/local/share/:/usr/share/:/etc/opt/kde3/share/:/opt/kde3/share/:/opt/gnome/share/"
    
60. declare -x XKEYSYMDB="/usr/X11R6/lib/X11/XKeysymDB"
    
61. declare -x XNLSPATH="/usr/X11R6/lib/X11/nls"
    

復(fù)制代碼

wind_ch

system函數(shù)返回的是執(zhí)行程序的退出狀態(tài). system(ls -l)最後也會打印0,

2者的不同懷疑是程序內(nèi)部處理輸出的問題

flw

$ type history
history is a shell builtin
$

珞水的大叔

我也試了一下
system("history")
報錯如下：
Can't exec "history": 沒有那個文件或目錄
為什么內(nèi)建函數(shù)用system執(zhí)行不了呢

wind_ch

Can't exec "history": 沒有那個文件或目錄
system是exec那個命令, 需要一個可執(zhí)行文件, history是內(nèi)建在shell中的, 沒有叫history的程序.
which history 是沒有結(jié)果的

飛鴻無痕

回復(fù) 8# wind_ch

thank you!!!

珞水的大叔

回復(fù) 8# wind_ch


    了解啦，多謝啊