Running Lex and Yacc Program in ubuntu

Easy Ways Guide to Run Lex and Yacc Programs on ubuntu.

This post will show you how to run Lex and Yacc programs easily on ubuntu 12.04

I have assumed that you have a working Ubuntu 12.04 LTS version installed on your system and the computer is connected to the network.

Ubuntu does not come installed with a lex and yacc compiler to do so install it first by
1. Opening the terminal
2. type - sudo apt-get install flex
3. enter your password

after installation of flex finishes
4. type - sudo apt-get install bison
5. enter your pasword.

Congratualtions Lex and Yacc have been installed on your system.

Running a Lex and Yacc program

for compiling a lex program
1. write the lex program in a file and save it as file.l (where file is the name of the file).
2. open the terminal and navigate to the directory where you have saved the file.l
3. type - lex file.l
4. then type - cc lex.yy.c -ll
5. then type - ./a.out

Your lex progam will be running now (provided it is correct).

for compiling lex and yacc together
1. write lex program in a file file.l and yacc in a file file.y
2. open the terminal and navigate to the directory where you have saved the files.
3. type lex file.l
4. type yacc file.y
5. type cc lex.yy.c y.tab.h -ll
6. type ./a.out

The lex and yacc will run succesfully now

Comments

  1. Unknown7 June 2014 at 10:39

    Thanks :) that is really helpful

    ReplyDelete
  2. Test1232 October 2014 at 02:35

    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    Package flex is not available, but is referred to by another package.
    This may mean that the package is missing, has been obsoleted, or
    is only available from another source

    E: Package 'flex' has no installation candidate

    ReplyDelete
  3. Unknown4 October 2014 at 03:25

    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    You might want to run 'apt-get -f install' to correct these:
    The following packages have unmet dependencies:
    bison : Depends: m4
    Depends: libbison-dev (= 1:2.5.dfsg-2.1) but it is not going to be installed
    Conflicts: bison:i386
    bison:i386 : Depends: libc6:i386 (>= 2.6) but it is not going to be installed
    Conflicts: bison
    flex:i386 : Depends: libc6:i386 (>= 2.11) but it is not going to be installed
    Recommends: gcc:i386 but it is not going to be installed or
    c-compiler:i386
    m4:i386 : Depends: libc6:i386 (>= 2.4) but it is not going to be installed
    E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

    ReplyDelete
  4. aish28 October 2014 at 03:58

    root@ubuntu:~/Desktop# lex intar.l
    root@ubuntu:~/Desktop# yacc intar.y
    root@ubuntu:~/Desktop# cc lex.yy.c y.tab.h -ll
    cc: error: y.tab.h: No such file or directory

    please provide a solution for this

    ReplyDelete
  5. GRK28 October 2014 at 22:54

    Thank you :)

    ReplyDelete
  6. Unknown22 November 2014 at 05:07

    It is not $ gcc lex.yy.c y.tab.h -ll
    it is $ gcc lex.yy.c y.tab c -ll
    because y.tab.h is just a header file that is included within the lex file to hold the references to the indentifiers in yacc. y.tab.c is the c file created as a result of the yacc program. gcc is a c compiler and needs a c file to compile.
    and do $ yacc -d prog.y
    you have left out -d there.

    ReplyDelete
    Replies
    1. Unknown8 April 2015 at 11:15

      Thanks for the perfect solution .. :)

      Delete
    2. Goforkanchan31 March 2017 at 01:55

      What is the use of -d in that command?

      Delete
  7. Unknown25 June 2015 at 02:48

    thanx for the help........

    ReplyDelete
  8. Unknown22 November 2015 at 07:16

    thank u helped me...

    ReplyDelete
  9. Anonymous8 December 2015 at 02:37

    Thanks a lot for sharing these valuable informations.Super blogging.Keep it up.
    web development oman

    ReplyDelete
  10. SRD5259 February 2016 at 22:26

    How do i install flex and bison on ubuntu 14.04? suggest something that will help for offline installtion once packages are dwonloaded.

    ReplyDelete
  11. Unknown2 May 2016 at 08:13

    /tmp/ccsOtGCV.o: In function `yylex':
    lex.yy.c:(.text+0x4f1): undefined reference to `yywrap'
    /tmp/ccsOtGCV.o: In function `input':
    lex.yy.c:(.text+0x102c): undefined reference to `yywrap'
    collect2: error: ld returned 1 exit status
    how to resolve his problem

    ReplyDelete
  12. Unknown10 May 2016 at 02:43

    ~/$ y.tab.h -ll
    y.tab.h: command not found
    can anyone help me out????

    ReplyDelete
  13. Unknown16 October 2016 at 10:00

    kamlesh@kamlesh-Inspiron-3537:~/Documents/Lex$ lex calc1.l
    kamlesh@kamlesh-Inspiron-3537:~/Documents/Lex$ cc lex.yy.c -ll
    calc1.l:3:23: fatal error: y.tab.h: No such file or directory
    #include "y.tab.h"
    ^
    compilation terminated.
    kamlesh@kamlesh-Inspiron-3537:~/Documents/Lex$

    solution please?

    ReplyDelete
  14. Unknown16 October 2016 at 10:46

    kamlesh@kamlesh-Inspiron-3537:~/Documents/Lex$ lex calc1.l
    kamlesh@kamlesh-Inspiron-3537:~/Documents/Lex$ yacc calc1.y
    calc1.y:22 parser name defined to default :"parse"
    conflicts: 4 shift/reduce

    ReplyDelete
  15. Ganesh17 October 2016 at 00:42

    🤓 good job ...

    ReplyDelete
  16. Unknown3 December 2016 at 02:28

    Ty so much I got it installed

    ReplyDelete
  17. Anonymous3 December 2016 at 20:29

    ak@ubuntu:~$ sudo apt-get install flex
    [sudo] password for ak:
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    Package flex is not available, but is referred to by another package.
    This may mean that the package is missing, has been obsoleted, or
    is only available from another source

    ReplyDelete
  18. Unknown25 March 2017 at 00:02

    can we compile and run only yacc file

    ReplyDelete
  19. Unknown13 April 2017 at 13:37

    minalm-2808@ubuntu:~$ lex cal.l

    minalm-2808@ubuntu:~$
    minalm-2808@ubuntu:~$ yacc -d cal.y
    minalm-2808@ubuntu:~$ ./a.out
    bash: ./a.out: No such file or directory
    minalm-2808@ubuntu:~$

    ReplyDelete
  20. Pratik12mukh13 April 2018 at 03:49

    cal.y:46 parser name defined to default :"parse"
    this erroe shows

    ReplyDelete
  21. Unknown1 February 2019 at 03:18

    lavada

    ReplyDelete
  22. Unknown1 February 2019 at 03:19

    it is good

    ReplyDelete
  23. Unknown6 October 2019 at 18:21

    If internet wouldn't have been existed it would have been very hard for programmers like us to learn ew things , thnx man izzat bacha li aapne !

    ReplyDelete

Post a Comment

Popular posts from this blog

Why the Apple M1 chip is too hyped - perspectives of an average user.

Why the M1 chip is too hyped - perspectives of an average user.  As of 10th June, 2021, I know this might seem controversial, but it is what it is. After watching at least 100+ YouTube video's about the new apple m1 silicon I have to come to the conclusion that I will not be buying the M1 silicon based computer anytime soon. Lets talk about myself: 1. Works at a corporate job as an Analyst dealing with lots of data. 2. Does programming in Python and other scripting languages occasionally on the personal computer which is a intel i5 (6th gen) Dell Desktop which I bought 2 years ago used for 250 dollars (roughly translating 18000 rupees). My next logical upgrade is to buy to a personal laptop for that added flexibility of being portable and I wanted to consider M1. This upgrade is an optional upgrade and I could delay buying this for upto 2 more years. Now it got me thinking, really hard, all the people on YouTube raving about the M1, *actually do* need the power that it offers in te...
Read more

For June 2021 the best Phone is the iPhone XR

With Samsung and OnePlus flagship phones increasing their costs everyday, if you want to get a flagship experience in June 2021 at the lowest price possible then I don't believe anything can beat the iPhone XR and here are the reasons why: -- It is available at its lowest price yet (you could grab one from anywhere between 300-500 dollars) -- Has the same OS that even the latest iPhone Pro Max has and hence the buttery smooth animations -- I doubt there is an app that is used by 99% of the users that works only in iPhone 12 and not on XR I would just buy an XR and subscribe to iCloud storage for for dollar a month and call it my "EcoSystem".
Read more