compile tslib1.4,----error: call to ‘__open_missing_mode’ declared with attribute error_warning: ignoring return value of ‘write’, declare-优快云博客

本文链接：https://blog.youkuaiyun.com/sunxiaopengsun/article/details/79474281

本文解决了一个GCC编译过程中出现的警告和错误问题，具体涉及到使用open函数时未正确提供参数导致的问题。通过调整代码，确保了当使用O_CREAT标志时，正确地指定了文件权限模式。

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problem:
---------------------
ts_calibrate.c: In function ‘main’:
ts_calibrate.c:234: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result
In file included from /usr/include/fcntl.h:205,
                 from /usr/include/sys/fcntl.h:1,
                 from ts_calibrate.c:20:
In function ‘open’,
    inlined from ‘main’ at ts_calibrate.c:227:
/usr/include/bits/fcntl2.h:51: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT in second argument needs 3 arguments
In function ‘open’,
    inlined from ‘main’ at ts_calibrate.c:229:
/usr/include/bits/fcntl2.h:51: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT in second argument needs 3 arguments
make[2]: *** [ts_calibrate.o] Error 1
make[2]: Leaving directory `/root/Qt_Tools/tslib/tests'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/root/Qt_Tools/tslib'
make: *** [all] Error 2
root@10.0.0.196:/root/Qt_Tools/tslib

---------------------------------------------

solution:

root@xx-desktop:~/Qt_Tools/tslib# gedit ./tests/ts_calibrate.c&

go to line227 &&line 229,

        if ((calfile = getenv("TSLIB_CALIBFILE")) != NULL) {
           cal_fd = open (calfile, O_CREAT | O_RDWR,0777));
       } else {
           cal_fd = open ("/etc/pointercal", O_CREAT | O_RDWR,0777));
       }

Because GCC strict syntax error checking.When using then OPEN function,the 2th parameter using "O_CREAT",you must add the 3th parameter ---0777.