The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
grep, egrep, fgrep, rgrep – print lines that match patterns Synopsisgrep [OPTION…] PATTERNS [FILE…] grep [OPTION…] -e PATTERNS … [FILE…] grep [OPTION…] -f PATTERN_FILE … [FILE…] Descriptiongrep searches for PATTERNS in each FILE. PATTERNS is one or more patterns separated by newline characters, and grep prints each line that matches a pattern. Typically PATTERNS should…
malloc, free, calloc, realloc, reallocarray – allocate and free dynamic memory Synopsis#include <stdlib.h> void *malloc(size_t size); void free(void *ptr); void *calloc(size_t nmemb, size_t size); void *realloc(void *ptr, size_t size); void *reallocarray(void *ptr, size_t nmemb, size_t size);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): reallocarray(): Since glibc 2.29: _DEFAULT_SOURCE Glibc 2.28 and earlier: _GNU_SOURCE DescriptionThe malloc()…
printf, fprintf, dprintf, sprintf, snprintf, vprintf, vfprintf, vdprintf, vsprintf, vsnprintf – formatted output conversion Synopsis#include <stdio.h> int printf(const char *format, …); int fprintf(FILE *stream, const char *format, …); int dprintf(int fd, const char *format, …); int sprintf(char *str, const char *format, …); int snprintf(char *str, size_t size, const char *format, …); #include <stdarg.h> int vprintf(const…
open, openat, creat – open and possibly create a file Synopsis#include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> int open(const char *pathname, int flags); int open(const char *pathname, int flags, mode_t mode); int creat(const char *pathname, mode_t mode); int openat(int dirfd, const char *pathname, int flags); int openat(int dirfd, const char *pathname, int flags, mode_t mode); /*…
ls – list directory contents Synopsisls [,OPTION/]… [,FILE/]… DescriptionList information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuvSUX nor –sort is specified. Mandatory arguments to long options are mandatory for short options too. -a, –all do not ignore entries starting with . -A, –almost-all do not list implied…