Reference: http://pubs.opengroup.org/onlinepubs/9699919799/functions/popen.html http://pubs.opengroup.org/onlinepubs/9699919799/functions/pclose.html Signed-off-by: Nikola Forró <nforro@xxxxxxxxxx> --- man3/popen.3 | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/man3/popen.3 b/man3/popen.3 index f075581..bafa42c 100644 --- a/man3/popen.3 +++ b/man3/popen.3 @@ -123,17 +123,18 @@ function waits for the associated process to terminate and returns the exit status of the command as returned by .BR wait4 (2). .SH RETURN VALUE -The -.BR popen () -function returns NULL if the +.BR popen (): +on success, returns a pointer to an open stream that +can be used to read or write to the pipe; +if the .BR fork (2) or .BR pipe (2) -calls fail, or if it cannot allocate memory. -.PP -The -.BR pclose () -function returns \-1 if +calls fail, or if the function cannot allocate memory, +NULL is returned. + +.BR pclose (): +on success, returns the exit status of the command; if .\" These conditions actually give undefined results, so I commented .\" them out. .\" .I stream @@ -141,10 +142,12 @@ function returns \-1 if .\".I stream .\" already "pclose()d", or if .BR wait4 (2) -returns an error, or some other error is detected. -In the event of an error, these functions set +returns an error, or some other error is detected, +\-1 is returned. +.PP +Both functions set .I errno -to indicate the cause of the error. +to an appropriate value in the case of an error. .SH ERRORS The .BR popen () -- 2.4.11 -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
