Questions tagged [execl]

execl() is a C library function which is used to replace the current process image with a new process image. It belongs to the family of exec() functions and prototyped in unistd.h.

execl() is a C library function which is used to replace the current process image with a new process image. It belongs to the familt of exec() functions and prototyped in unistd.h.

The Function Prototype

int execl(const char *path, const char *arg, ...);

where,

  • The first argument is the name of a file that is to be executed.
  • The const char *arg and subsequent arguments (if any) can be thought of as arg0, arg1, ..., argn. Together they describe a list of one or more pointers to null-terminated strings that represent the argument list available to the executed program.

Return Value

The various exec() functions only return if an error has occurred. The return value is -1, and errno is set to indicate the error.

Check the Main page for more details.

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Execl dont start the program

I have two programs, one of them calls another through execl, but it doesn't start. Here is the calling program: #include #include int main(int argc, int *argv[]) { printf("Program %s executes", argv[0]); execl("hello", " ",…
Tomas
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Why can't I use execl() to run a bash script?

I'm trying to run a bash script from a website button on a raspberry pi, where the script is located in home/pi/. The code snippet below shows my current solution. Whenever the website button is pressed, it calls this block of code in a c file.…
N. Sunilkumar
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Pipeline bash commands echo and bc into a C program

I'm trying to do a little C program that realize a pipeline of two bash commands : echo $arithmeticOperation | bc $arithmeticOperation is a string taken as input. The program works fine executing first command, but when i run the second one, i get…
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Using forks and os.execl in Python is giving me an OSError

I have a larger program (150 lines or so) but this seems to be the only issue I have. I have managed to cut down the problem and have made it into a smaller program. Essentially, it forks the program and tries to execute a linux command (I am…
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How to pass environment variables using execle() for /bin/login?

This is similar to how to set environment variable when execle executes bash? I am trying to use execle() in C to perform /bin/login and pass the environment variable to target shell. And can not make it work. I have tried by passing environment as…
Klemen
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How to mock fork and execlp system calls in c++ unit test using gmock framework?

I have existing C++ code, which creates a child process using fork() system call. And child process executes linux command using execlp() system call. Now I want to test this code using gmock framework with 100% code coverage. I googled a lot but I …
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How to run odaslive program from c file

So I am trying to call a program from within a c file I am making but the only way I've been able to do that is by using the system() function which causes error on its own. To run the program in terminal I use; ~/odas/bin/odaslive -vc…
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running programme in parallel using fork()

I am trying to complete a tutorial on running a parallel programme in C using fork() and execl commands. The user enters the number of inputs(N). The next N lines contain a number <= 10 digits. My programme will calculate the number of prime…
calveeen
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Make children process in pause until receiving parent's signal to execute an execl task

I am trying to develop a simple railroad simulation following the answer to the question Make children process wait until receiving parent's signal. My task: I have exactly 5 process representing trains. I need to create these 5 process (T1, T2, T3,…
Gianni Spear
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How to change time zone(TZ=UTC) output in execl() function.

I am using running one binary eg. 'ls -la' in my c code with execl() function and reading return status of child process. execl("/bin/ls", "ls", "-la", NULL); and receiving child status by waitpid(pid, &status, 0 ); function. But i need my out put…
Abhitesh khatri
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Run sleep in background in C language (Linux)

I am trying to call the sleep function with '&' in order to run it in thebackground. The C program is going to replace the Terminal of linux. The command line in C program (of Linux) has to include an execl command, but it is not working. The…
חיים חדד
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Handle exactly all signals of type SIGUSR1 that come to parent process. C

I want to write a program which will create N children, using fork() function. Each child will wait from 0 to 3 seconds and then it'll send it's parent exactly one signal SIGUSR1. Parent handles all of these signals. The problem is that my program…
grzegorzs
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execl() call succeeds in main(), fails in function

I'm a beginner to systems programming and I am currently trying to play around with basic server/client communication using sockets, pipes, etc More specifically I want to be able to connect as a client and input something like '/bin/echo hello'.…
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How can Execl return but WIFEXITED and WEXITSTATUS don't indicate an error?

I am executing a binary with execl. This is all working OK, waitpid returns a correct pid, WIFEXITED(pidstatus) gives a 1 and WEXITSTATUS(pidstatus) a 0. Now I change the permissions for that binary to restrict its access. The binary is not being…
Lieuwe
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Variable as argument to winexe command in execl function is not working

I want to execute winexe command through execl function call in a C program. It works if i hard code credentials and machine name in execl call as follows execl("winexe","winexe","-U","Domain/Username%Password","//hostname","ipconfig",NULL) But if…
Kang
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