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Top Forums Shell Programming and Scripting Help in understanding the following commands Post 302362447 by Scrutinizer on Friday 16th of October 2009 04:57:16 AM
Old 10-16-2009
Hi,

$$ stands for process id of the running process. To include this in a filename is a way of making the file or directory unique.

The second expression is missing a closing parenthesis. But it set k to the number of lines that do not contain the characters " ", "+", "-","0", "1" or formfeed. Whether the formfeed detection will work depends on your version of grep. If it doesn't then this code will also exclude lines that contain the character "f" from the count and that probably is not what was intended.

The third expression means if the 24 characters starting at position 2 in the variable "file" contain 13 or more digits then print the character "N" concatenated by the content of the variable "file" .

Last edited by Scrutinizer; 10-16-2009 at 06:05 AM..
 

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ustrtok(3alleg4)						  Allegro manual						  ustrtok(3alleg4)

NAME
ustrtok - Retrieves tokens from a string. Allegro game programming library. SYNOPSIS
#include <allegro.h> char *ustrtok(char *s, const char *set); DESCRIPTION
This function retrieves tokens from `s' which are delimited by characters from `set'. To initiate the search, pass the string to be searched as `s'. For the remaining tokens, pass NULL instead. Warning: Since ustrtok alters the string it is parsing, you should always copy the string to a temporary buffer before parsing it. Also, this function is not re-entrant (ie. you cannot parse two strings at the same time). Example: char *word; char string[]="some-words with dashes"; char *temp = ustrdup(string); word = ustrtok(temp, " -"); while (word) { allegro_message("Found `%s' ", word); word = ustrtok(NULL, " -"); } free(temp); RETURN VALUE
Returns a pointer to the token, or NULL if no more are found. SEE ALSO
uconvert(3alleg4), ustrchr(3alleg4), ustrrchr(3alleg4), ustrstr(3alleg4), ustrpbrk(3alleg4), ustrtok_r(3alleg4), allegro_message(3alleg4), ustrncpy(3alleg4), exgui(3alleg4) Allegro version 4.4.2 ustrtok(3alleg4)
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