1 files changed, 90 insertions, 0 deletions
diff --git a/src/command.c b/src/command.c
new file mode 100644
index 0000000..c413502
--- /dev/null
+++ b/src/command.c
@@ -0,0 +1,90 @@
+#include "../include/command.h"
+#include <unistd.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+
+#define READ_END 0
+#define WRITE_END 1
+
+int tsl_command_exec(char **args, ProgramOutputCallback output_callback, void *userdata) {
+    int fd[2];
+    pid_t pid;
+
+    /* 1 arguments */
+    if(args[0] == NULL)
+        return -1;
+    
+    if(pipe(fd) == -1) {
+        perror("Failed to open pipe");
+        return -2;
+    }
+
+    pid = fork();
+    if(pid == -1) {
+        perror("Failed to fork");
+        return -3;
+    } else if(pid == 0) { /* child */
+        dup2(fd[WRITE_END], STDOUT_FILENO);
+        close(fd[READ_END]);
+        close(fd[WRITE_END]);
+
+        execvp(args[0], args);
+        return 0;
+    } else { /* parent */
+        int result = 0;
+        int status;
+        char buffer[2048];
+        int exit_status;
+
+        close(fd[WRITE_END]);
+        for(;;) {
+            ssize_t bytes_read = read(fd[READ_END], buffer, sizeof(buffer) - 1);
+            if(bytes_read == 0) {
+                break;
+            } else if(bytes_read == -1) {
+                int err = errno;
+                fprintf(stderr, "Failed to read from pipe to program %s, error: %s\n", args[0], strerror(err));
+                result = -err;
+                goto cleanup;
+            }
+
+            buffer[bytes_read] = '\0';
+            if(output_callback && !output_callback(buffer, bytes_read, userdata))
+                break;
+        }
+
+        if(waitpid(pid, &status, 0) == -1) {
+            perror("waitpid failed");
+            result = -5;
+            goto cleanup;
+        }
+
+        if(!WIFEXITED(status)) {
+            result = -4;
+            goto cleanup;
+        }
+
+        exit_status = WEXITSTATUS(status);
+        if(exit_status != 0) {
+            char **arg = args;
+            fprintf(stderr, "Failed to execute program (");
+            
+            while(*arg) {
+                if(arg != args)
+                    fputc(' ', stderr);
+                fprintf(stderr, "'%s'", *arg);
+                ++arg;
+            }
+            fprintf(stderr, "), exit status %d\n", exit_status);
+            result = -exit_status;
+            goto cleanup;
+        }
+
+        cleanup:
+        close(fd[READ_END]);
+        return result;
+    }
+}